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In this article, we examine how the COVID-19 pandemic, an exogenous shock to the United States education system, shaped teachers’ readiness and willingness to engage in professional development (PD). We borrow the concept of exogenous shocks from economics and sociology to illustrate how education practice can be driven as much by factors outside the field (e.g., viral outbreaks) as by those within it (e.g., policy and scholarship). Using the four substantive domains in Appova and Arbaugh’s (2018) framework on teachers' motivation to learn in PD—teacher education and PD, educational psychology, andragogy and adult learning, and policy and accountability—we argue that teacher motivation, rather than mere PD structure or content, is the true linchpin of teacher learning. In that light, we describe some of the pandemic’s demotivational effects on teachers’ learning in the U.S. and offer a roadmap for scholars to center motivation in future PD research. We outline several pathways of inquiry, including a renewed focus on links between teacher motivation and PD effectiveness, the generation and application of new measures and models of teachers’ motivation to learn, and the use of PD as an instrument for teacher resilience and efficacy after an exogenous shock. Keywords: professional development, teacher learning, teacher motivation, COVID-19, pandemic

Background Breakthrough infections post-COVID-19 vaccination increase with waning immunity and typically produce milder disease than infections in unvaccinated individuals. We investigated immuno-virologic responses and COVID-19 symptom burden upon breakthrough infection in participants from a Phase 3 study of 2-dose primary series AZD1222 vaccination (NCT04516746) to explore disease attenuation. Methods Study participants who experienced protocol-defined COVID-19 symptoms initiated a series of illness visits over 28 days with collection of sera, nasopharyngeal (NP) swabs and saliva samples (SS), and documentation of symptoms (data-cut off: July 30, 2021). For baseline-seronegative participants with PCR-confirmed SARS-CoV-2 infection ≥15 days after dose 2 of AZD1222 or placebo we assessed: anti-SARS-CoV-2 spike (S), nucleocapsid (N) and neutralizing antibody (Ab) titers by multiplex immunoassay and SARS-CoV-2 pseudovirus assay in sera; viral load by quantitative RT-PCR in NP swabs; and viral shedding by qualitative and quantitative RT-PCR in SS. Data were stratified by age and SARS-CoV-2 variant, and time since primary series dose 2. Results Illness Day 1 (ILL-D1) S Ab GMTs in AZD1222 vaccinees were similar to peak GMTs seen 14 days after dose 2 of AZD1222 and were higher vs placebo at all timepoints. The magnitude of S Ab response differed by age: median GMTs were lower at ILL-D1 and higher at ILL-D14 in vaccinees aged ≥65 vs 18–64 years (Fig.1). ILL-D1 overall, SARS-CoV-2 ancestral, alpha, and epsilon variant viral load titers in NP swabs were lower in vaccinees vs placebo (Fig 2). Mean viral load in NP swabs and viral shedding titers in SS were lower in vaccinees vs placebo at all timepoints. Vaccinees reported fewer COVID-19 symptoms than placebo participants, and experienced shorter symptom duration, particularly for fatigue and difficulty breathing. Figure 1. SARS-CoV-2 spike IgG antibody titers upon SARS-CoV-2 infection by participant age in AZD1222 vaccinees and placebo recipients during illness visits Figure 2. Quantification of viral load (nasopharyngeal swabs quantitative viral titer) by SARS-CoV-2 variant at Illness Visit Day 1 Conclusion Improved S Ab responses, lower viral loads, and reduced symptom burden upon breakthrough infection in vaccinees vs placebo recipients, suggest that robust recall responses to AZD1222 vaccination may attenuate COVID-19 disease severity and duration. These findings alongside data on cellular immune responses to breakthrough infection will inform understanding of protective immunity to SARS-CoV-2 infection. Disclosures Magdalena E. Sobieszczyk, MD, MPH, Bill and Melinda Gates Foundation: Grant/Research Support|Gilead Sciences: Grant/Research Support|Janssen Global Services, LLC: Grant/Research Support|Merck: Grant/Research Support|National Institute of Allergy and Infectious Diseases (NIAID): Grant/Research Support|National Institutes of Health (NIH): Grant/Research Support|Sanofi Pasteur Inc.: Grant/Research Support Ann R. Falsey, MD, BioFire Diagnostics: Grant/Research Support|Janssen: Grant/Research Support|Merck, Sharp and Dohme: Grant/Research Support|Novavax: Advisor/Consultant|Pfizer: Grant/Research Support Anne F. Luetkemeyer, MD, AstraZeneca: Grant/Research Support|Gilead Sciences: Grant/Research Support Grant C. Paulsen, MD, AstraZeneca: Grant/Research Support|Moderna: Grant/Research Support|Pfizer: Grant/Research Support Sharon A. Riddler, MD, National Institute of Allergy and Infectious Diseases (NIAID): Grant/Research Support|National Institutes of Health (NIH): Grant/Research Support|Novimmune: Advisor/Consultant Merlin L. Robb, MD, Walter Reed Army Institute of Research: Advisor/Consultant Charlotte-Paige M. Rolle, MD, MPH, Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria|Janssen: Board Member|ViiV Healthcare: Board Member|ViiV Healthcare: Grant/Research Support|ViiV Healthcare: Honoraria|Vindico CME: Honoraria Beverly E. Sha, MD, Gilead Sciences: Grant/Research Support|MATEC: Honoraria|University of Chicago: Grant/Research Support|US Government: Grant/Research Support Bahar Ahani, BSC, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Anastasia A. Aksyuk, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Himanshu Bansal, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Justin A. Green, MD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Brett Jepson, MS, AstraZeneca: Contractor via Cytel Jill Maaske, MD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Kathryn Shoemaker, MS, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Stephanie Sproule, MMath, AstraZeneca: Contractor via Joule/System One Ann Marie Stanley, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Deidre Wilkins, BSC, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Tonya L. Villafana, PhD, MPH, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds Elizabeth J. Kelly, PhD, AstraZeneca: Employee|AstraZeneca: Stocks/Bonds.

The purpose of this study was to explore why and how a prototypically “effective” teacher professional development (PD) effort, reciprocal peer coaching (RPC), fell short. Despite RPC’s conformity with long-espoused best practices in PD—content-specificity, extended duration, collaboration, inquiry, and self-direction—only two in eight music teachers who began the 5-month coaching and observation trajectory completed it. We used instrumental case study analysis to understand teachers’ decisions to continue in or prematurely withdraw from RPC. Findings revealed motivational factors such as collaboration and affirmative support, growth-in-practice learning, and content relevance were, for the majority of participants, overcome by demotivational factors related to participants’ perceived lack of agency in shaping their work context and the incoherence and insufficiency of their policy environments. We advance implications for PD providers, researchers, and policymakers.

Music teachers in urban, suburban, and rural communities face a multitude of challenges and opportunities. To identify and examine specific experiences that may be unique to rural general music teachers, we recruited six teacher-participants to complete a 5-week online professional development (PD) course for this exploratory study. We created a teacher-led approach for this PD, implementing topics and solutions generated by the participants. Using qualitative content analysis, we found two categories of themes in the online discussion posts that either connected or disconnected our participants with other music teachers on their general music context or their geographic setting. Although participants clearly articulated the influences of setting and place-based pedagogy, we found shared issues related to general music that transcended location. Implications for future PD include the importance of online delivery methods and developing PD differentiated by teaching contexts and geographic settings.

Causality assessment for suspected drug-induced liver injury (DILI) during drug development and following approval is challenging. The IQ DILI Causality Working Group (CWG), in collaboration with academic and regulatory subject matter experts (SMEs), developed this manuscript with the following objectives: (1) understand and describe current practices; (2) evaluate the utility of new tools/methods/practice guidelines; (3) propose a minimal data set needed to assess causality; (4) define best practices; and (5) promote a more structured and universal approach to DILI causality assessment for clinical development. To better understand current practices, the CWG performed a literature review, took a survey of member companies, and collaborated with SMEs. Areas of focus included best practices for causality assessment during clinical development, utility of adjudication committees, and proposals for potential new avenues to improve causality assessment. The survey and literature review provided renewed understanding of the complexity and challenges of DILI causality assessment as well as the use of non-standardized approaches. Potential areas identified for consistency and standardization included role and membership of adjudication committees, standardized minimum dataset, updated assessment tools, and best practices for liver biopsy and rechallenge in the setting of DILI. Adjudication committees comprised of SMEs (i.e., utilizing expert opinion) remain the standard for DILI causality assessment. A variety of working groups continue to make progress in pursuing new tools to assist with DILI causality assessment. The minimum dataset deemed adequate for causality assessment provides a path forward for standardization of data collection in the setting of DILI. Continued progress is necessary to optimize and advance innovative tools necessary for the scientific, pharmaceutical, and regulatory community. Supplementary Information The online version contains supplementary material available at 10.1007/s40264-021-01051-5.

The nasal mucosa is an important initial site of host defense against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, intramuscularly administered vaccines typically do not achieve high antibody titers in the nasal mucosa. We measure anti-SARS-CoV-2 spike immunoglobulin G (IgG) and IgA in nasal epithelial lining fluid (NELF) following intramuscular vaccination of 3,058 participants from the immunogenicity substudy of a phase 3, double-blind, placebo-controlled study of AZD1222 vaccination (ClinicalTrials.gov: NCT04516746). IgG is detected in NELF collected 14 days following the first AZD1222 vaccination. IgG levels increase with a second vaccination and exceed pre-existing levels in baseline-SARS-CoV-2-seropositive participants. Nasal IgG responses are durable and display strong correlations with serum IgG, suggesting serum-to-NELF transudation. AZD1222 induces short-lived increases to pre-existing nasal IgA levels in baseline-seropositive vaccinees. Vaccinees display a robust recall IgG response upon breakthrough infection, with overall magnitudes unaffected by time between vaccination and illness. Mucosal responses correlate with reduced viral loads and shorter durations of viral shedding in saliva.

Spinal muscular atrophy (SMA) is a rare neuromuscular disease with a rapidly evolving treatment landscape. To better meet the needs of trial sponsors and the patient community in the United States (US) in this evolving context, Cure SMA established a clinical trial readiness program for new and prospective SMA clinical trial sites. Program development was informed by a review of the SMA clinical trial landscape, successful NMD trial and care networks, and factors important to effective trial conduct in SMA. The program was piloted in 2018 with a virtual site readiness evaluation, a trial readiness toolkit, and a readiness program for physical therapists and clinical evaluators. Nine US research hospitals participated in the pilot. Cure SMA evaluated the pilot program and resources through feedback surveys, which supported the program’s relevance and value. Since 2018, the program has been expanded with additional sites, new best practices toolkits, and workshops. In partnership with Cure SMA, SMA Europe is also extending programming to European countries. The program is significant as an example of a patient advocacy group working successfully with pharmaceutical companies, other patient advocacy organizations, and research hospitals to promote trial readiness, and may serve as a model for organizations in other regions and diseases.

This article examines the relationship between the professional learning of music teachers and their capacity and opportunity to act and engage agentically with the structures and discourses of mus...

Specialist arts and music teachers around the world experience intense feelings of professional isolation. Such feelings lead to negative consequences on their professional growth, psychological we...

The purpose of this Arts Education Policy Review special issue was to connect international music teacher professional development (PD) policies by theme and draw policy parallels and intersections...

The diagnosis and management of drug-induced liver injury (DILI) remains a challenge in clinical trials in drug development. The qualification of emerging biomarkers capable of predicting DILI soon after the initiation of treatment, differentiating DILI from underlying liver disease, identifying the causal entity, and assigning appropriate treatment options after DILI is diagnosed are needed. Qualification efforts have been hindered by lack of properly stored and consented biospecimens that are linked to clinical data relevant to a specific context of use. Recommendations are made for biospecimen collection procedures, with the focus on clinical trials, and for specific emerging biomarkers to focus qualification efforts.

The purpose of this article is to make policy recommendations based on the authors’ experiences with, and research about, reflective, differentiated, and teacher-generated music teacher pro...

The Arkansas Department of Children and Family Services (DCFS) has reduced the use of therapeutic residential care (e.g., group homes, residential treatment centers) for youth placed in child welfa...

New York Times. Snoop Dogg. Estelle Jorgensen. Thoreau. Dapper Dan. Harlem. Hip-hop. Kafka. Ethnography. Sushi. Charter schools. Robert Moses. Michael Jackson. We Are the World. Chicago Bulls. Cosb...

This final chapter of The Oxford Handbook of Preservice Music Teacher Education in the United States synthesizes suggestions from the previous 42 chapters in the areas of teacher education practice, research, and policy. It reviews the boundaries that need to be pushed in music teacher education, such as those related to issues of diversity, equity, and inclusion. It summarizes the challenges to that work and directs the reader to specific chapters that have covered this subject in detail. Personal reflections from P-12 teachers are incorporated throughout the chapter to illustrate the boundaries they have tried to push and the challenges they have face in doing so. Before concluding, the chapter discusses agendas for change within the field.

This chapter provides strategies for creative practices that will enrich elementary general music methods courses. The crucial choices made by instructors about the content and structure of elementary general music are interrogated, including how various methodologies are approached and how traditional practices—even the term methods itself—may be re-evaluated and reconsidered. Recommendations are made for retitling and expanding the scope of this course to reflect its truly foundational nature within music education. Ways to establish positive learning environments are discussed, including specific ideas instructors may use to develop fieldwork practicums, teach lesson planning, and be aware of cultural considerations for responsive pedagogy within these courses. The chapter closes with a call to expand preservice teachers’ views on the multitudinous ways elementary students may musically, collaboratively, and creatively experience music in the school setting.

Paralogous enzymes arise from gene duplication events that confer a novel function, although it is unclear how cross-reaction between the original and duplicate protein interaction network is minimized. We investigated HPr:EIsugar and NPr:EINtr, the initial complexes of paralogous phosphorylation cascades involved in sugar import and nitrogen regulation in bacteria, respectively. Although the HPr:EIsugar interaction has been well characterized, involving multiple complexes and transient interactions, the exact nature of the NPr:EINtr complex was unknown. We set out to identify the key features of the interaction by performing binding assays and elucidating the structure of NPr in complex with the phosphorylation domain of EINtr (EINNtr), using a hybrid approach involving X-ray, homology, and sparse nuclear magnetic resonance. We found that the overall fold and active-site structure of the two complexes are conserved in order to maintain productive phosphorylation, however, the interface surface potential differs between the two complexes, which prevents cross-reaction.

There are populations of musicians who demonstrate considerable success-making music in formal school music ensembles and also in their own rock, digital, and ethnic groups in the larger musical community. We suggest helpful insights into the phenomenon of switching between various ways of being musical can be gleaned from the linguistic theory of code-switching. Although authors have identified a disconnect between the narrowly categorised music taught in schools and the wider variety of music in society, we have identified musical ‘code-switchers:’ people adept at navigating multiple musical worlds. The purpose of this study is to examine the experiences and perceptions of these musicians who have demonstrated skill and comfort switching between formal ensembles in a school of music and informal ensembles of multiple genres outside of the school and to examine the viability of using code-switching to better understand flexible, comprehensive musicianship. Participants indicated both musical and ...

Collaborative professional development (PD) efforts are increasingly popular and successful across the United States. In this article, we highlight the voice of the teacher in brief descriptions of PD efforts that support collaboration as a key component of meaningful music teacher PD. To draw a vivid picture of the potential and possibilities in models of music teacher collaborative PD, we connect eight practicing teachers’ positive PD experiences to recommendations from recent research findings. We also make suggestions for music teacher educators about the implications of these findings about the establishment of a disposition in preservice teachers toward valuing collaborative development.

Membrane proteins serve important functions in cells such as nutrient transport, motility, signaling, survival and virulence, yet constitute only ~1% percent of known structures. There are two types of membrane proteins, α-helical and β-barrel. While α-helical membrane proteins can be found in nearly all cellular membranes, β-barrel membrane proteins can only be found in the outer membranes of mitochondria, chloroplasts, and Gram-negative bacteria. One common bottleneck in structural studies of membrane proteins in general is getting enough pure sample for analysis. In hopes of assisting those interested in solving the structure of their favorite β-barrel outer membrane protein (OMP), general protocols are presented for the production of target β-barrel OMPs at levels useful for structure determination by either X-ray crystallography and/or NMR spectroscopy. Here, we outline construct design for both native expression and for expression into inclusion bodies, purification using an affinity tag, and crystallization using detergent screening, bicelle, and lipidic cubic phase techniques. These protocols have been tested and found to work for most OMPs from Gram-negative bacteria; however, there are some targets, particularly for mitochondria and chloroplasts that may require other methods for expression and purification. As such, the methods here should be applicable for most projects that involve OMPs from Gram-negative bacteria, yet the expression levels and amount of purified sample will vary depending on the target OMP.

This study presents findings of a formative evaluation of an innovative pilot program designed to reunify and reintegrate foster youth with complex mental and behavioral needs in residential treatment centers or therapeutic foster care with their families in the community. Data collection methods included in-depth structured case file reviews and semi-structured interviews with the youth, as well as their caregivers, Child Protective Services caseworkers, and pilot program staff. The participants provided important insights regarding system, program, and case-level barriers to the successful reunification of these youth back into the community. Training, practice, and policy recommendations are discussed.

Teacher study groups are often thought to be effective professional development structures. Such teacher communities may foster teacher learning through a collaborative culture and the codification of group members' collective knowledge. However, not all study groups are effective professional development. This article is a discussion of factors that may contribute to the success or failure of collaborative teacher study. Recommendations for practice are provided, with a focus on music teacher study groups.

SummaryMisfolded, luminal endoplasmic reticulum (ER) proteins are retrotranslocated into the cytosol and degraded by the ubiquitin/proteasome system. This ERAD-L pathway requires a protein complex consisting of the ubiquitin ligase Hrd1p, which spans the ER membrane multiple times, and the membrane proteins Hrd3p, Usa1p, and Der1p. Here, we show that Hrd1p is the central membrane component in ERAD-L; its overexpression bypasses the need for the other components of the Hrd1p complex. Hrd1p function requires its oligomerization, which in wild-type cells is facilitated by Usa1p. Site-specific photocrosslinking indicates that, at early stages of retrotranslocation, Hrd1p interacts with a substrate segment close to the degradation signal. This interaction follows the delivery of substrate through other ERAD components, requires the presence of transmembrane segments of Hrd1p, and depends on both the ubiquitin ligase activity of Hrd1p and the function of the Cdc48p ATPase complex. Our results suggest a model for how Hrd1p promotes polypeptide movement through the ER membrane.

The purpose of this study was to compare the perceptions of summers-only MM (SO) graduates to academic year (AY) graduates. Research questions included: (a) How do program graduates describe their experiences in the SO or AY program, (b) What are the similarities and differences in the perceptions of the two groups (SO and AY), and (c) What suggestions do participants have regarding the advantages and disadvantages of various MM program designs? This study used a qualitative formative program evaluation design. Data included an online survey, email journals, and individual interviews with nine program graduates. Findings include descriptive participant profiles as well as themes organized by the following categories: (a) motivations for and reflections on the degree, (b) issues of time, and (c) experiences within a community.

Little is known about the dynamic process of membrane protein folding, and few models exist to explore it. In this study we doubled the number of Escherichia coli outer membrane proteins (OMPs) for which folding into lipid bilayers has been systematically investigated. We cloned, expressed, and folded nine OMPs: outer membrane protein X (OmpX), OmpW, OmpA, the crcA gene product (PagP), OmpT, outer membrane phospholipase A (OmpLa), the fadl gene product (FadL), the yaet gene product (Omp85), and OmpF. These proteins fold into the same bilayer in vivo and share a transmembrane β-barrel motif but vary in sequence and barrel size. We quantified the ability of these OMPs to fold into a matrix of bilayer environments. Several trends emerged from these experiments: higher pH values, thinner bilayers, and increased bilayer curvature promote folding of all OMPs. Increasing the incubation temperature promoted folding of several OMPs but inhibited folding of others. We discovered that OMPs do not have the same ability to fold into any single bilayer environment. This suggests that although environmental factors influence folding, OMPs also have intrinsic qualities that profoundly modulate their folding. To rationalize the differences in folding efficiency, we performed kinetic and thermal denaturation experiments, the results of which demonstrated that OMPs employ different strategies to achieve the observed folding efficiency.

The epidermal growth factor receptors (erbB) constitute an important class of single pass transmembrane receptors involved in the transduction of signals important for cell proliferation and differentiation. Receptor association is a key event in the signal transduction process, but the molecular basis of this interaction is not fully understood. Previous biochemical and genetic studies have suggested that the single transmembrane helices of these receptor proteins might play a role in stabilizing the receptor complexes. To determine if the erbB transmembrane domains could provide a driving force to stabilize the receptor dimers, we carried out a thermodynamic study of these domains expressed as C-terminal fusion proteins with staphylococcal nuclease. Similar fusion constructs have been used successfully to investigate the oligomerization and association thermodynamics of a number of transmembrane sequences, including that of glycophorin A. Using SDS-PAGE analysis and sedimentation equilibrium analytical ultracentrifugation, we do not find strong, specific homo or hetero-interactions between the transmembrane domains of the erbB receptors in micellar solutions. Our results indicate that any preferential interactions between these domains in micellar solutions are extremely modest, of the order of 1 kcal mol(-1) or less. We applied a thermodynamic formalism to assess the effect of weakly interacting TM segments on the behavior of a covalently attached soluble domain. In the case of the ligand-bound EGFR ectodomain, we find that restriction of the ectodomain to the micellar phase by a hydrophobic TM, even in the absence of strong specific interactions, is largely sufficient to account for the previously reported increase in dimerization affinity.

We have used sedimentation equilibrium analytical ultracentrifugation to measure the free energy change for the glycophorin A transmembrane helix-helix dimerization in C14 betaine micelles. By varying the amount of micellar C14 betaine, we show that the protein association reaction in the micellar C14 phase behaves as an ideal-dilute solution. In this hydrophobic environment, the mole-fraction standard state free energy change for self-association of the SNGpA99 glycophorin A construct is -5.7 (+/-0.3, N=5) kcal mol(-1) at 25 degrees C. Compared with previous results carried out in C(8)E(5) micellar solutions, the free energy of dimerization is 1.3 kcal mol(-1) less favorable in C14 betaine micelles. In contrast, when considered on a per-interface basis, the formation of the glycophorin A transmembrane dimer in C14 betaine micelles may be more favorable than the association of several designed transmembrane peptides.

HER2 (also known as Neu, ErbB2) is a member of the epidermal growth factor receptor (EGFR; also known as ErbB) family of receptor tyrosine kinases, which in humans includes HER1 (EGFR, ERBB1), HER2, HER3 (ERBB3) and HER4 (ERBB4). ErbB receptors are essential mediators of cell proliferation and differentiation in the developing embryo and in adult tissues, and their inappropriate activation is associated with the development and severity of many cancers. Overexpression of HER2 is found in 20-30% of human breast cancers, and correlates with more aggressive tumours and a poorer prognosis. Anticancer therapies targeting ErbB receptors have shown promise, and a monoclonal antibody against HER2, Herceptin (also known as trastuzumab), is currently in use as a treatment for breast cancer. Here we report crystal structures of the entire extracellular regions of rat HER2 at 2.4 A and human HER2 complexed with the Herceptin antigen-binding fragment (Fab) at 2.5 A. These structures reveal a fixed conformation for HER2 that resembles a ligand-activated state, and show HER2 poised to interact with other ErbB receptors in the absence of direct ligand binding. Herceptin binds to the juxtamembrane region of HER2, identifying this site as a target for anticancer therapies.

We are two music education professors with a long history of multilayered professional collaborations: first, Colleen as advisor to Ann Marie as a doctoral student, followed by a mentor and new professor relationship, and now as coresearchers, coauthors, and critical friends. Throughout our 10-year relationship—beginning with Ann Marie’s entry into the doctoral degree programme in music education at University of Michigan in 2005, a programme of study that Colleen directed—common goals have connected us.

This chapter is an overview of the myriad ways researchers have investigated typical general music classroom activities. The studies are organized depending on researcher positioning, and whether the research took place in or outside the classroom. The stance of each study is reviewed in terms of its balance between embracing classroom complexity and isolating individual student or teacher actions. Literature on the general music teacher is presented, including studies that examined teachers’ working conditions, how teachers acquire and use music content knowledge, and the development of various types and levels of teaching practice. Recommendations for future research are made, including the value of attending to accurate portrayals of researcher and participant voice, and the need for further research on what constitutes developmentally appropriate, meaningful musical learning activities.

Misfolded, luminal endoplasmic reticulum (ER) proteins must be recognized before being degraded by a process called ERAD-L. Using site-specific photocrosslinking in Saccharomyces cerevisiae, we tested luminal interactions of a glycosylated ERAD-L substrate with potential recognition components. Major interactions were observed with Hrd3p. These are independent of the glycan and of other ERAD components, and can occur throughout the length of the unfolded substrate. The lectin Yos9p only interacts with a polypeptide segment distant from the degradation signal. Hrd3p may thus be the first substrate-recognizing component. Der1p appears to have a role in a pathway that is parallel to that involving Hrd3p.Structured summary of protein interactionssCPY physically interacts with sCPY by cross-linking study (View interaction)Hrd3 and sCPY physically interact by cross-linking study (View interaction)

Regulated molecular interactions are essential for cellular function and viability, and both homo- and hetero-interactions between all types of biomolecules play important cellular roles. This chapter focuses on interactions between membrane proteins. Knowing both the stoichiometries and stabilities of these interactions in hydrophobic environments is a prerequisite for understanding how this class of proteins regulates cellular activities in membranes. Using examples from the authors' work, this chapter highlights the application of analytical ultracentrifugation methods in the determination of these parameters for integral membrane proteins. Both theoretical and practical aspects of carrying out these experiments are discussed.

Regulated molecular interactions are essential for cellular function and viability, and both homo- and hetero-interactions between all types of biomolecules play important cellular roles. This chapter focuses on interactions between membrane proteins. Knowing both the stoichiometries and stabilities of these interactions in hydrophobic environments is a prerequisite for understanding how this class of proteins regulates cellular activities in membranes. Using examples from the authors' work, this chapter highlights the application of analytical ultracentrifugation methods in the determination of these parameters for integral membrane proteins. Both theoretical and practical aspects of carrying out these experiments are discussed.

Just 25 years ago the Anfinsen thermodynamic hypothesis was shown to be valid for membrane proteins. Despite the complex biological machinery required for their in vivo assembly and in face of the chemically heterogeneous, anisotropic nature of their biological lipid bilayer "solvent", the evidence continues to suggest that membrane proteins are equilibrium structures. The progress in finding conditions in vitro to investigate the physical origins of their stabilities is the focus of this article. We catalogue in vitro folding studies in detergent micelles and in lipid bilayers. We consider the unique technical obstacles to folding studies of membrane proteins, and we highlight the progress that has been made in quantitative descriptions of membrane protein stability.

The hydrogen bonding of polar side-chains has emerged as an important theme for membrane protein interactions. The crystal structure of the dimeric state of the transmembrane beta-barrel protein outer membrane phospholipase A (OMPLA) revealed an intermolecular hydrogen bond mediated by a highly conserved glutamine side-chain (Q94). It has been shown that the introduction of a polar residue can drive the association of model helices, and by extension it was presumed that the glutamine hydrogen bond played a key role in stabilizing the OMPLA dimer. However, a thermodynamic investigation using sedimentation equilibrium ultracentrifugation in detergent micelles reveals that the hydrogen bond plays only a very modest role in stabilizing the dimer. The Q94 side-chain is hydrogen bonded intramolecularly to residues Y92 and S96, but amino acid substitutions at these positions suggest these intramolecular interactions are not responsible for attenuating the strength of the intermolecular Q94 hydrogen bond. Other substitutions suggested that hydration of the local environment around Q94 may be responsible for the modest strength of the hydrogen bond. Heat inactivation experiments with the variants suggest that the Y92-Q94-S96 network may instead be important for thermal stability of the monomer. These results highlight the context dependence and broad range of interactions that can be mediated by polar residues in membrane proteins.

Outer membrane phospholipase A (OMPLA) is a unique, integral membrane enzyme found in Gram-negative bacteria and is an important virulence factor for pathogens such as Helicobacter pylori. This broad-specificity lipase degrades a variety of lipid substrates, and it plays a direct role in adjusting the composition and permeability of bacterial membranes under conditions of stress. Interestingly, OMPLA shows little preference for the lipid headgroup and, instead, the length of the hydrophobic acyl chain is the strongest determinant for substrate selection by OMPLA, with the enzyme strongly preferring substrates with chains equal to or longer than 14 carbon atoms. The question remains as to how a hydrophobic protein like OMPLA can achieve this specificity, particularly when the shorter chains can be accommodated in the binding pocket. Using a series of sulfonyl fluoride inhibitors with various lengths of acyl chain, we show here that the thermodynamics of substrate-induced OMPLA dimerization are guided by the acyl chain length, demonstrating that OMPLA uses a unique biophysical mechanism to select its phospholipid substrate.

Outer membrane phospholipase A (OMPLA) is a widely conserved transmembrane enzyme found in Gram-negative bacteria, and it is implicated in the virulence of a number of pathogenic organisms. The regulation of the protein's phospholipase activity is not well understood despite the existence of a number of high resolution structures. Previous biochemical studies have demonstrated that dimerization of OMPLA is a prerequisite for its phospholipase activity, and it has been shown in vitro that this dimerization is dependent on calcium and substrate binding. Therefore, to fully understand the regulation of OMPLA, it is necessary to understand the stability of the protein dimer and the extent to which it is influenced by its effector molecules. We have used sedimentation equilibrium analytical ultracentrifugation to dissect the energetics of Escherichia coli OMPLA dimerization in detergent micelles. We find that calcium contributes relatively little stability to the dimer, while interactions with the substrate acyl chain are the predominant force in stabilizing the dimeric conformation of the enzyme. The resulting thermodynamic cycle suggests that interactions between effector molecules are additive. These energetic measurements not only provide insight into the activation of OMPLA, but they also represent the first quantitative investigation of the association energetics of a transmembrane beta-barrel. This thermodynamic study allows us to begin to address the differences between protein-protein interfaces in transmembrane proteins with a helical fold to those of a beta-barrel fold and to more fully understand the forces involved in membrane protein interactions.