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Pluripotent stem cells (PSCs) can self-renew indefinitely in culture while retaining the potential to differentiate into virtually all normal cell types in the adult animal. Due to these remarkable properties, PSCs not only provide a superb system to investigate mammalian development and model diseases, but also hold promise for regenerative therapies. Autophagy is a self-digestive process that targets proteins, organelles, and other cellular contents for lysosomal degradation. Here, we review recent literature on the mechanistic role of different types of autophagy in embryonic development, embryonic stem cells (ESCs), and induced PSCs (iPSCs), focusing on their remodeling functions on protein, metabolism, and epigenetics. We present a perspective on unsolved issues and propose that autophagy is a promising target to modulate acquisition, maintenance, and directed differentiation of PSCs. Macroautophagic flux is accentuated during early embryonic development and in embryonic stem cells (ESCs), and upregulation of macroautophagy facilitates reprogramming of somatic cells to iPSCs. Macroautophagy sustains quality and homeostasis of proteins and organelles in stem cells. It also remodels proteome, metabolome, and epigenome to facilitate the acquisition and maintenance of the pluripotent state. Mitophagy regulates mitochondrial integrity, dynamics, and function in stem cells. Mitophagy also reduces the number of mitochondria to enable glycolytic metabolism and minimize redox stress. Chaperone-mediated autophagy (CMA) is maintained at low levels in ESCs and is markedly increased upon differentiation. CMA modulates intracellular levels of an obligatory cofactor for DNA and histone demethylases, thereby regulating epigenetic landscape and fate decisions of ESCs. [ABSTRACT FROM AUTHOR]

A study was conducted on Daxx, a novel signaling protein that activates Jun N-terminal kinase (JNK) and apoptosis. Results indicate that overexpression of Daxx increases Fas-mediated apoptosis and activates the JNK pathway. While Daxx's C-terminal portion reacts with the Fas-binding domain JNK and apoptosis interact with a different region. Furthermore, although the apoptotic pathway is compatible with the FADD pathway, it is also sensitive to Bcl-2 and JNK's dominant-negative pathway inhibitor.

Herein, a variety of single-phase full-spectrum emission phosphors doped with Eu2+ were synthesized. Under the 350 nm excitation, as K+ and Y3+ were introduced into Ca 10 Na(PO 4) 7 (CNP):1.5%Eu2+, respectively, the emission color of Ca 9.85 K y Na (1- y) (PO 4) 7 :1.5%Eu2+ (0 ≤ y ≤ 1.0) was tuned from yellow to cyan, while that of Ca (9.85- z) NaY 0.667 z (PO 4) 7 :1.5%Eu2+ (0 ≤ z ≤ 1.0) was tuned from yellow to green. The internal quantum yield (QY) of Ca 9·85 K 0·4 Na 0·6 (PO 4) 7 (CKNP):1.5%Eu2+ and Ca 9·45 NaY 0·267 (PO 4) 7 (CNYP):1.5%Eu2+ reached 47.47 % and 27.11 %, respectively. The introduction of K+ or Y3+ made Eu2+ selectively occupy the Ca sites and led to changes in the local environment of Eu2+, allowing for spectral tuning emission. In addition, the luminescence intensity of the samples retained 54.59 % and 31.34 % of their room temperature values. Eventually, two white light emitting diode (WLED) devices were fabricated, combining the synthesized white emitting phosphors with 365 nm ultraviolet (UV) chips. They exhibited high color rendering indices of 84.7 and 77.0, along with low correlated color temperatures of 5435 K and 5023 K. The Commission Internationale de L'Eclairage (CIE) color coordinates were (0.3349, 0.3975) and (0.3517, 0.4366), respectively. The results pointed to the phosphors' potential suitability for use in the WLED sector. [ABSTRACT FROM AUTHOR]

The reaction of alkenes with ozone has great effect on atmospheric oxidation, its transient species can produce OH radicals and contribute to the formation of secondary organic aerosols (SOA). In the present study, the reaction of tetramethylethene (TME) with ozone was investigated using self-assembled low temperature matrix isolation system. The TME and ozone were co-deposited on a salt plate at 15 K, and then slowly warmed up the plate. The first transient species primary ozonide (POZ) was detected, indicating that the reaction followed Criegee mechanism. Then POZ began to decompose at 180 K. However, secondary ozonide (SOZ) was not observed according to Criegee mechanism. Probably, Criegee Intermediate (CI) did not react with inert carbonyl of acetone, but with remaining TME formed tetra-methyl epoxide (EPO). Image, graphical abstract [ABSTRACT FROM AUTHOR]

Optically transparent and structurally flexible metamaterial absorbers (MMAs) are widely used in many practical applications. However, the realization of such MMAs requires both thickness reduction and bandwidth enhancement, which remains a challenge task. As a multi-objective optimization problem, it is a time-consuming and resource-demanding process. Guided by prior-knowledge, two degrees of freedom are taken into account in the design, namely the structure of unit-cells and their spatial arrangement. In this way, the multi-objective optimization problem is simplified into a two-step problem. A general procedure based on machine-learning (ML) method is proposed to solve this problem. First, an artificial neural network (ANN) is used to map the configuration parameters of a type of meta-atom onto its reflection coefficients; then, a dynamic graph convolutional neural network (DGCNN) is trained to realize the synthesis of quasi-periodic distributed MMA array; finally, combined with the differential evolution (DE) algorithm, the optimized configuration of the meta-atoms and their optimum distribution are obtained. Based on the proposed procedure, an ultrathin optically transparent and flexible MMA is designed, fabricated and further verified by experiments. The designed MMA realizes 87% absorption bandwidth covering 6.22 GHz–19.42 GHz (103% relative bandwidth) with the thickness only 3. 3 mm (0. 068 λ L) , which approaches the theoretical limit 1 / 17 λ L . And its averaged transparency is about 63% at the wavelength range 500 – 800 mm. The whole design process is achieved 50 times faster than the conventional full-wave simulation, which convincingly demonstrates the superiority of the proposed method. [ABSTRACT FROM AUTHOR]

Summary MicroRNAs play an important role in T cell responses. However, how microRNAs regulate CD8 T cell memory remains poorly defined. Here, we found that miR-150 negatively regulates CD8 T cell memory in vivo. Genetic deletion of miR-150 disrupted the balance between memory precursor and terminal effector CD8 T cells following acute viral infection. Moreover, miR-150-deficient memory CD8 T cells were more protective upon rechallenge. A key circuit whereby miR-150 repressed memory CD8 T cell development through the transcription factor c-Myb was identified. Without miR-150, c-Myb was upregulated and anti-apoptotic targets of c-Myb, such as Bcl-2 and Bcl-xL, were also increased, suggesting a miR-150-c-Myb survival circuit during memory CD8 T cell development. Indeed, overexpression of non-repressible c-Myb rescued the memory CD8 T cell defects caused by overexpression of miR-150. Overall, these results identify a key role for miR-150 in memory CD8 T cells through a c-Myb-controlled enhanced survival circuit. [ABSTRACT FROM AUTHOR]

Deep soil stores a large amount of organic carbon (C) and nitrogen (N). However, little is known regarding the interactions between soil C and net N mineralization in deep soil, which complicates the prediction of ecosystem C and N dynamics. In this study, a 150-day laboratory soil incubation experiment was performed under 20 °C and 25 °C to investigate the influence of soil depth and warming on C and net N mineralization and their relationship. Soils were collected from a Hapludalfs profile in a subtropical forest with three depth intervals: 0–10 (topsoil), 10–30 (midsoil), and 30–60 cm (subsoil). Soil microbial community-level physiological profiling (CLPP) was conducted to investigate the role of the microbial community in C and N mineralization. The results demonstrated that both C and net N mineralization rates in subsoil were significantly lower than in topsoil. Compared to topsoil, subsoil had lower temperature sensitivity of C mineralization and relatively higher temperature sensitivity of net N mineralization. Cumulative soil C and net N mineralized were positively correlated in topsoil with the mineralized N per mineralized C showed as 0.19 and 0.31 at 20 °C and 25 °C, respectively. However, there was no significant correlation between cumulative soil C and net N mineralized in subsoil due to the low amount of net N mineralization. The lack of labile C source and degradable organic N were believed to limit the net N mineralization in subsoil. The microbial community in topsoil used relatively more easily decomposable carbohydrates and carboxylic acids, which favored C mineralization. In contrast, the microbial community in subsoil had relatively high utilization of amino acids (N-containing substrates), which indicated there was N limitation. This distinguished substrate utilization patterns of microbial communities could explain the observed C and N mineralization rates among the soil depths, and suggests that the microbial community played an important role in soil C and N mineralization. The decoupled relationships between soil C and net N mineralization in deep soil and their differentiated responses to warmer temperatures among soil depths indicated that deep soil should be considered separately from topsoil for ecosystem C and N cycling, especially for ecosystem C dynamic models. [ABSTRACT FROM AUTHOR]

Highlights: [•] Thermal influential factors affecting crude oil temperature in double pipelines system have been analyzed in detail. [•] Insulating layer and changes of crude oil physical characteristic are considered to correspond with practice. [•] Ambient temperature is a key parameter to determine pipeline interval. [ABSTRACT FROM AUTHOR]

Abstract: Rubber sleeve is sealing component of underground packers, the rubber will occur corrosion or failure under the acid medium environment, which causes gas leak and leads to the security problems of wellbore. In the paper, corrosion testing was carried out to AFLAS rubber using HTHP autoclave in the harsh environment with the pressure 60MPa, temperature 175°C, test period 7 days and the compositions of the gas phase are 20vol% H2S, 5vol% CO2, 75vol% CH4. Comparing and analyzing the changes of properties in gas and liquid phase before and after testing, such as quality, volume, tensile properties, hardness, permanent deformation, etc. The experimental results show that AFLAS rubber in gas and liquid phase has no dissolution phenomenon; moreover, tensile properties were weakened, hardness decreased and permanent deformation increased. While bubbling of AFLAS rubber in gas phase was more serious than in liquid phase, the swelling was on the contrary. Although AFLAS rubber is a good kind of anti-acid medium rubber, its mechanical properties is weakened in harsh environment. Therefore, in order to improve the effective seal life of packers in corroded environment, the corrosion influence on packer rubber should be considered when it is designed and used in high sour gas fields. [Copyright &y& Elsevier]

Abstract: Plants have been used to restore vegetation in desert region in Shapotou, where naturally biological soil crusts (BSCs) have formed after planting for several years. However, few works have been done on the allelopathic effects between the plants and soil microalgae in BSCs currently. In this study, we investigated the chemical compositions of volatile oil of Artemisia ordosica and its allelopathic effects on photosynthetic system II (PSII) and antioxidant system of Palmellococcus miniatus, a green algae isolated from BSCs. 37 components, consisted of 17 terpenoids, 14 alcohols, 2 esters, 2 ketones and other 2 components were identified in the volatile oil from A. ordosica by GC–MS analysis. High concentration of volatile oil could significantly inhibit the growth and photosynthetic activity (Fv/Fm), and decreased the photosynthetic parameters by affecting photon absorption, electron transport and the reaction center of PSII of P. miniatus, and also cause the significant increase of superoxide dismutase (SOD; EC 1.15.1.) activity, peroxidase (POD; EC 1.11.1.7) activity, reactive oxygen evolution (ROS) and malondialdehyde (MDA) contents of P. miniatus through the combined effects of components in volatile oil. The results indicated that the emission of volatile oil of A. ordosica could inhibit the growth, photosynthesis of P. miniatus through the oxidative damage, and thus might negatively affect the development of BSCs. [Copyright &y& Elsevier]

Abstract: Inhibitor of apoptosis (IAP) proteins are a family of evolutionarily conserved proteins that regulate apoptosis as well as other cellular processes. The functions of many IAPs are defined by their RING domains, which possess E3 ubiquitin ligase activity and promote proteasomal degradation of an increasing number of target proteins. In this chapter, we describe the methods used in our laboratories to study the IAP''s E3 activity. [Copyright &y& Elsevier]

The emergence of cancer from diverse normal tissues has long been rationalized to represent a common set of fundamental processes. However, these processes are not fully defined. Here, we show that forced expression of glucose-6-phosphate dehydrogenase (G6PD) affords immortalized mouse and human cells anchorage-independent growth in vitro and tumorigenicity in animals. Mechanistically, G6PD augments the NADPH pool by stimulating NAD+ kinase-mediated NADP+ biosynthesis in addition to converting NADP+ to NADPH, bolstering antioxidant defense. G6PD also increases nucleotide precursor levels through the production of ribose and NADPH, promoting cell proliferation. Supplementation of antioxidants or nucleosides suffices to convert immortalized mouse and human cells into a tumorigenic state, and supplementation of both is required when their overlapping metabolic consequences are minimized. These results suggest that normal cells have a limited capacity for redox balance and nucleotide synthesis, and overcoming this limit might represent a key aspect of oncogenic transformation. • G6PD can effectively transform immortalized fibroblasts and epithelial cells • Forced G6PD expression bolsters antioxidant defense and nucleotide synthesis • G6PD activates NAD kinase to stimulate NADP+ biosynthesis and converts NADP+ to NADPH • Exogenous antioxidants and nucleosides suffice to transform murine and human cells The basic elements required for oncogenic transformation remain undefined. By analyzing glucose-6-phosphate dehydrogenase (G6PD)-mediated oncogenic transformation, Zhang et al. show that upregulation of antioxidant defense and nucleotide production suffices to transform murine and human cells. Therefore, oncogenic transformation may involve overcoming a limited redox balance capacity and nucleotide precursor availability. [ABSTRACT FROM AUTHOR]

CaTi 2 O 4 (OH) 2 :Eu3+, CaTiO 3 :Eu3+ and [CaTi 2 O 4 (OH) 2 –CaTiO 3 ]:Eu3+ were synthesized by a solvothermal method without the help of templates or surfactants. And their structures, luminescence properties, and photocatalytic properties were systematically studied. The RIR (reference intensity ratio) data of CaTi 2 O 4 (OH) 2 were first investigated via X-ray diffraction (XRD), thus the ratios of each phase in the (m%CaTi 2 O 4 (OH) 2 -n%CaTiO 3):3%Eu3+ biphasic mixture was determined. The bandgap value of CaTi 2 O 4 (OH) 2 :3%Eu3+ is 0.28 eV less than that of CaTiO 3 :3%Eu3+. The specific surface area of CaTi 2 O 4 (OH) 2 is 8.2 times larger than that of CaTiO 3. Compared with CaTiO 3 :Eu3+, the CaTi 2 O 4 (OH) 2 :Eu3+ showed stronger luminescence intensity. The Judd-Ofelt theory analysis show that the Eu3+ ions in CaTi 2 O 4 (OH) 2 :Eu3+ have low local symmetry, high Eu–O bonds covalence and low ligands electron density. The photocatalytic properties of CaTi 2 O 4 (OH) 2 :y%Eu3+, CaTiO 3 :x%Eu3+ and [62.2%CaTi 2 O 4 (OH) 2 -37.8%CaTiO 3 ]:3% Eu3+ were comparatively studied in detail. The band-gap value of [62.2 % CaTi 2 O 4 (OH) 2 –37.8%CaTiO 3 ]:3%Eu3+ is significantly reduced due to the presence of heterojunctions compared to CaTi 2 O 4 (OH) 2 :y%Eu3+ and CaTiO 3 : x%Eu3+. The built-in electric potential at heterojunction interface will guide electrons and holes to move in opposite directions, therefore [CaTi 2 O 4 (OH) 2 –CaTiO 3 ]:Eu3+ has excellent photocatalytic activity. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: This study was to describe the synthesis of complexes of gadolinium diethylenetriaminepentaacetic acid conjugates of low-molecular-weight chitosan oligosaccharide Gd-DTPA-CSn (n =6, 8, 11) as a new class of contrast agent as well as its magnetic property in a pilot magnetic resonance imaging. The efficacy of the contrast agent was assessed by measuring the longitudinal relaxivity (r 1), FLASH imaging in phantoms in vitro and signal intensity in vivo of the rat abdominal axial imaging. The r 1 of Gd-DTPA-CS 11 was up to 11.65mM−1·s−1, which was 3 times higher than that of the analogous MRI contrast agent Gd-DTPA in commercial use. In vivo MR images of rat obtained with Gd-DTPA-CS 11 showed strong signal enhancement in liver and the vessels of the liver parenchyma during the extended period of time. The present study suggests that the new synthesized gadolinium complexes can be used as a new class of practical liver-specific MRI contrast agent because of its superior performance compared with Gd-DTPA. [Copyright &y& Elsevier]

• PolyQ overexpression sensitizes tumor cells to NK cell cytolysis through inducing accumulation of misfolded proteins. • Abnormal transcriptome changes induced by polyQ protein predisposes tumor cells to death upon NK cell cytolysis. • PolyQ protein in NK cells compromises NK cell cytolytic activity through inducing an exhaustion-like status. Patients with Huntington's diseases display reduced tumor incidence mediated by unclear mechanisms. Besides, the effects of characteristic overexpression of 97 polyglutamine protein (polyQ protein) on tumor surveillance by the host immune system have not been investigated. NK cells are cytotoxic innate lymphocytes that sense and kill stressed and transformed cells through recognition of abnormal molecular patterns. Here, we found that polyQ protein induced the accumulation of misfolded proteins in tumor cells and sensitized these tumor cells to NK cell cytolysis in vitro. Transcriptome analysis showed that polyQ protein overexpression caused an abnormal transcriptome changes in tumor cells, which might predispose these tumor cells to death upon NK cell cytolysis. However, on the other hand, polyQ protein in NK cells compromised NK cell cytolytic activity through forcing the accumulation of misfolded proteins. Furthermore, polyQ overexpression enriched oxidative phosphorylation related gene set in NK cells, which might lead to an exhaustion-like status of NK cells with reduced cytolytic activity. Therefore, our study shows that polyQ protein overexpression in tumors alone, but not in both tumor cells and NK cells, might result in increased tumor rejection by NK cells, revealing a dual role of polyQ protein on tumor surveillance by the immune system. [ABSTRACT FROM AUTHOR]

The aim of this meta-analysis is to assess the associations between two most widely investigated polymorphisms (rs3746544 and rs1051312) in the 3′UTR of the SNAP-25 gene and susceptibility of ADHD. Two investigators selected related studies and assessed methodological quality independently. Six studies were included in this meta-analysis for a total of 715 cases and 655 controls. There is no apparent association between rs3746544 polymorphisms and risk of ADHD. However, subgroup analysis based on ethnicity demonstrated a strong association between rs3746544 polymorphism and ADHD in the subset of Asian participants, but not among Caucasians. Compared to the T allele, the allele G was associated with a significantly decreased risk of developing ADHD in the Asian population (odds ratio (OR) = 0.70, 95% confidence interval (CI) = 0.52–0.95, p = 0.02). The association between the TT genotype and ADHD risk was also significantly increased as compared to G/T (OR = 1.56, 95% CI = 1.00–2.44, p = 0.05) and the dominant genetic model (GG + GT vs. TT: OR = 1.51, 95% CI = 1.07–2.13, p = 0.02). For the rs1051312 SNP, being homozygous for the minor allele (C/C) was associated with a 3.66 higher odds of ADHD as compared to cases homozygous for the major allele (T/T) (95% CI = 1.64–8.13, p = 0.001), and 3.57 higher odds as compared to heterozygous (C/T) carriers (95% CI = 2.01–12.90, p < 0.001). Our results suggest that the polymorphisms rs3746544 and rs1051312 may increase the odds of developing ADHD. Additional studies are needed to confirm these findings. [ABSTRACT FROM AUTHOR]

Rhesus (rh) but not human (hu) TRIM5α potently restricts human immunodeficiency virus (HIV)-1 infection. It is not clear why huTRIM5α fails to effectively block HIV infection, but it is thought to have a lower affinity for the viral core. Using primary human CD4 T cells, we investigated the ability of huTRIM5α, rhTRIM5α, and the huTRIM5αR323-332 B30.2/SPRY patch-mutant to form cytoplasmic bodies, postulated as key components of the HIV-1 restriction apparatus. Both rhTRIM5α and huTRIM5αR323-332 formed pronounced cytoplasmic bodies, whereas cytoplasmic bodies in T cells overexpressing huTRIM5α were present but more difficult to detect. As expression of all three TRIM5α orthologs was similar at the RNA level, we next investigated the role of protein stability in conferring TRIM5α-mediated HIV-1 restriction. Both steady-state and pulse-chase experiments revealed that the huTRIM5α protein was much less stable than rhTRIM5α, and this difference correlated with higher self-ubiquitination activity. Using a stabilized form of huTRIM5α in which the steady-state expression level was more similar to rhTRIM5α, we observed comparable HIV-1 restriction activity in multi-round HIV-1 challenge assays. Lastly, primary human CD4 T cells expressing a stabilized huTRIM5α were protected from HIV-1-mediated destruction in vivo, indicating that efforts to stabilize huTRIM5α should have significant long-term therapeutic value. [ABSTRACT FROM AUTHOR]

Integrated three-dimensional seismic, logging, sediment cores, and geochemical testing data were collected from Guangzhou Marine Geological Survey 3 and 4 hydrate drilling expeditions and used in this study for a comprehensive investigation of the geological and geophysical features and accumulation mechanism of hydrates in the first offshore gas-hydrate production test region (GHPTR) in the Shenhu area of the South China Sea. Seismic signatures indicative of disseminated hydrates and free gas include the bottom simulating reflector (BSR), gas chimney, and mud diapir associated with enhanced seismic reflections, acoustic blanking, masking, and chaotic appearance have been observed. The acoustic travel-time responses, density, and compensated neutron three porosity log analysis, high-precision grid tomography inversion analysis, and constrained sparse spike inversion confirm the presence of free gas below the gas-hydrate-bearing zone (GHBZ). Free-gas-bearing zones have significantly different p-wave impedances and low-velocity anomalies than the overlying GHBZ and surrounding strata. These anomalous zones are controlled by the structural attitude of the reservoir strata, which are characterized as inter-bedded stratigraphic units. Variations in the type and geological characteristics of the hydrocarbon migration pathways were observed between sites W18 and W19 on the western ridge and sites W11 and W17 on the eastern ridge in the GMGS study area. The efficiency of gas migration in the western ridge may be higher than that in the eastern ridge, resulting in variations in hydrate gas types, thickness of the GHBZ, and gas migration flux and accumulation. Except for site W11, hydrates were recovered below the structure I inferred BSR at sites W17, W18, and W19. The gas-hydrate stability zone calculations reveal that the structure I hydrate stability zone differs from the BSR depth and is generally shallower than the base of the logging anomaly, indicating the coexistence of structure I and II hydrates. The BSR is not indicative of the BGHSZ; it is rather regarded as a transitional indicator of structure I and II gas hydrates in the GHPTR. The appearance of free gas and hydrates below the structure I inferred BSR indicates that the Shenhu area is characterized by a complex hydrate formation and accumulation system resulting from the supply of biogenic and thermogenic gases. Despite fine-grained host sediments predominating the GHPTR, the coupling of favorable conditions including efficient hydrocarbon generation, sufficient gas supply, multiple pathways for gas migration, and relatively high reservoir porosity have led to the development of highly saturated gas-hydrate accumulations within relatively thick sedimentary sections, which demonstrates a significant resource potential. Image 1 • Gas hydrate petroleum system of the China first offshore hydrate production test region is investigated. • Gas hydrate and underlying free gas are evaluated based on velocity and acoustic impedance inversion. • The BSR represents a transitional indicator of structure I and structure II gas hydrate. • Presence of foraminifera is not a prerequisite for the emergence of high-saturation hydrates. [ABSTRACT FROM AUTHOR]

Frataxin is the protein that is down-regulated in Friedreich ataxia (FRDA), an autosomal recessive genetic disease caused by an intronic GAA repeat expansion in intron-1 of the FXN gene. The GAA repeats result in epigenetic silencing of the FXN gene and reduced expression of the cytosolic full-length frataxin (1−210) protein. Full length frataxin translocates to the mitochondria, leading to formation of mature frataxin (81–210) formed by cleavage of the mitochondrial targeting sequence at K-80 of the full-length protein. There are currently no approved treatments for FRDA, although experimental approaches involving up-regulation or replacement of mature frataxin protein through numerous approaches are being tested. Many of the pre-clinical studies of these experimental approaches are conducted in mouse and monkey models as well as in human cell lines. Consequently, well-validated antibodies are required for use in western blot analysis to determine whether levels of various forms of frataxin have been increased. Here we examined the specificity of five commercially available anti-frataxin antibodies and determined whether they detect mature frataxin in mouse heart tissue. Four protein standards of monkey, human, and mouse frataxin as well as mouse heart tissue were examined using polyacrylamide gel electrophoresis (PAGE) in combination with western blot analysis. One antibody failed to detect any of the frataxin standards or endogenous frataxin in mouse heart tissue. Three of the antibodies detected a protein in mouse heart tissue that ran slightly faster on PAGE (at 23.4 kDa) to that predicted for full-length frataxin (23.9 kDa). One antibody detected all four frataxin standards as well as endogenous mouse mature frataxin in mouse tissue. Significantly, this antibody, which will be useful for monitoring mature frataxin levels in monkey, human, and mouse tissues, did not detect a protein in mouse heart tissue at 23.4 kDa. Therefore, antibodies detecting the immunoreactive protein at 23.4 kDa could be misleading when testing for the up-regulation of frataxin in animal models. [ABSTRACT FROM AUTHOR]