Search

BACKGROUND: Lung cancer is the leading cause of cancer mortality in China. The clinicopathologic features and genetic profile of Chinese lung cancer patients need to be investigated. This study evaluated the gene mutation profile, analyzed the frequency of concurrent genes in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients, and determined its prognostic value. METHODS: We collected the clinical data from 151 initially diagnosed patients NSCLC. Tumor samples underwent targeted next-generation sequencing (NGS). Progression-free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. RESULTS: Among the 151 participants, the mutational profile revealed alterations in 29 genes, where TP53 (37.09%) and EGFR (30.46%) exhibited the highest mutation rates. Mutations in the EGFR gene were most prevalent (40%) in adenocarcinoma (LUAD) and were only present in 8.8% of participants with squamous cell carcinoma (LUSC). The most frequently mutated genes in LUAD patients were TP53 (47%), followed by KRAS (11.7%). In all 39 participants with EGFR mutations, TP53, KRAS, PIK3CA, APC, and FBXW7 were also mutated. Those with only EGFR mutation appeared to have a better prognosis; however, the difference was not statistically significant. Tumor mutational burden (TMB) was roughly significantly increased in patients who harbored EGFR and other mutant driver genes, compared with only EGFR mutant patients. The TMB value was significantly higher in those with P53 mutation than in P53 wild-type patients. CONCLUSIONS: We described the genetic profiles of NSCLC and compared the difference in genetic profiles between LUAD and LUSC. The concomitant genetic alterations might be a poor prognostic factor for patients with EGFR mutation, and TMB might be prognostically related to the co-mutations of EGFR and other genes.

Currently, little attention has been paid to reducing carbon dioxide (CO2) emissions of Gansu, and the two-dimensional decoupling model has been rarely used to study the relationship between the economic development and CO2 emissions, especially in western China (e.g., Gansu). Thus, here, we first used the Logarithmic Mean Divisia Index (LMDI) to decompose the driving factors of Gansu’s CO2 emissions between 2000–2017 and then analyzed the decoupling relationship by using the two-dimensional model. Results showed: (1) Gansu’s CO2 emissions increased from 7805.70 × 104 t in 2000 to 19,896.05 × 104 t in 2017. The secondary industry accounted for the largest proportion in Gansu’s CO2 emissions, followed by the tertiary industry and the primary industry. (2) The economic output showed the dominant driving effect on Gansu’s CO2 emissions growth with the cumulative contribution rate of 201.94%, followed by the effects of industrial structure, population size, and energy structure, and their cumulative contribution rates were 9.68%, 7.81%, and 3.05%, respectively. In contrast, the energy intensity effect presented the most obvious mitigating effect with the cumulative contribution rate of −122.49%. (3) The Environmental Kuznets Curve (EKC) between CO2 emissions and economic growth was demonstrated the inverted U-shape in Gansu. The two-dimensional decoupling status was the low level-weak decoupling (WD-LE) during 2000–2017. Thus, dropping the proportion of the secondary industry, reducing the use of carbon-intensive fuel like coal, introducing advanced technologies, and increasing the investment of new energy might effectively restrain the growth of Gansu’s CO2 emissions.

Dissolved organic matter (DOM) is generally thought to impact the bioavailability of heavy metals. However, the source of wetland DOM and its interaction with heavy metals remain poorly understood. Fluorescence excitation emission matrices (EEMs)-fluorescence regional integration (FRI) coupling techniques and chromophoric dissolved organic matter (CDOM) was used to explore the source of DOM of Poyang Lake including water body, soil and plants, and the effects on morphological changes of heavy metals. The results showed that the best DOM extraction effect can be obtained with the soil-water mass ratio 1:10, centrifuged at 4 000 rpm for 30 min, and the 0.45 μm glass fiber filter by orthogonal test. There were four types of peaks of DOM in water body of Poyang Lake, which was input mainly by land source, while six types of peaks (ACTDBE) were observed in soil. Soil DOM is highly humified with large molecular weight. More types of fluorescent peaks were observed in plant and the content of DOM in plants was higher than that of water body and soil due to the plant proteins. The content of fulvic acid was less than tryptophan in DOM of Triarrhena lutarioriparia and Phragmites communis in Longkou, while the opposite were in other samples. Furthermore, pot experiment illustrated that DOM had an activation effect on Cd, Cu and Zn and a passivation effect on Cr and Pb with the increase of DOM content. After the addition of exogenous DOM, Cr, Pb and Zn were immobilized by the function together with DOM and plants, while Cd and Cu were activated.

Background In 2017, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) removed spirometry as a criterion for classifying GOLD risk groups (A-D, low-high risk). Methods In this cross-sectional observational study in China, we used the GOLD 2016 (spirometry included) and 2018 (spirometry eliminated) criteria for classifying GOLD risk groups to describe: the proportion of patients with chronic obstructive pulmonary disease (COPD) in each GOLD risk group; disease severity; demographics and comorbidities. Patients aged ≥40 years with a clinical COPD diagnosis for ≥1 year were included. During a single study visit, patients completed the COPD assessment test, modified Medical Research Council (mMRC) dyspnea scale assessment, and spirometry tests. Demographics, medical history, and treatment data were recorded. Results In total, 838 patients were included. Most patients were male (86.4%), ≥65 years old (58.6%), and current or former smokers (78.5%). By GOLD 2016, the highest proportion of patients were Group D (42.8%), followed by B (28.2%). By GOLD 2018, the highest proportion of patients were Group B (57.3%), followed by A (25.5%). A total of 296 patients (35.3%) were reclassified, either from Group C to Group A or from Group D to Group B. Overall, 36.2% of patients were receiving treatment concordant with GOLD 2016 recommendations; 34.1% were not receiving any inhaled medication. Conclusions The distribution of COPD severity shifted from a high-risk category (by GOLD 2016) to a low-risk category (by GOLD 2018). The high proportion of patients not receiving maintenance medication reflects a high level of under-treatment of the disease.

The aim of this study was to investigate the expression of Kif18A in cancerous and paracancerous tissues from 100 patients with nonsmall cell lung cancer (NSCLC). This was a prospective study of 100 patients with pathologically confirmed NSCLC (adenocarcinoma and squamous cell carcinoma [SCC], n = 50/group) that were operated at the Quanzhou First Hospital Affiliated to Fujian Medical University between June 2015 and December 2016. Kif18A protein expression in cancerous and paracancerous normal tissues was detected by western blot and immunohistochemistry. The expression of the Kif18A protein was higher in adenocarcinoma and SCC tissues than in the corresponding paracancerous normal tissues. The expression of the Kif18A protein was higher in highly differentiated tumors, in patients with lymph node metastasis (vs no lymph node metastasis), adenocarcinoma, and in stage III NSCLC. There were no associations between Kif18A expression and age, gender, and pathologic type. The expression of the Kif18A protein by immunohistochemistry was higher in NSCLC tissues than in normal tissues, and was associated with tumor differentiation, lymph node metastasis, and TNM staging. These results could provide a theoretical basis for novel molecular targeted therapies against NSCLC.

BACKGROUND: Interferon (IFN) is widely used in clinical practice and nebulization inhalation is one of the commonly used routes of administration. However, nebulization drugs such as interferon-α (IFN-α) with large molecular weights may deposit in the membrane of the breathing filters, causing its resistance to gradually increase. Thus, our study explores the effect of IFN-α and other nebulization drugs on the resistance of breathing circuit filters under invasive mechanical ventilation. METHODS: We divided 96 breathing filters into eight groups. The baseline group was not treated while the blank group was installed but were not nebulized. The remaining groups received jet nebulized or vibrating nebulized with either normal saline, Combivent, Amphotericin B, or IFN-α at a frequency of once every 12 hours separately and were removed from the breathing circuit after 24 hours. The resistance of the filter of each group was then measured and statistical comparisons were made. RESULTS: Filter resistance of the IFN-α jet nebulization group was greater than that of the other groups, and there were statistical differences except for the Amphotericin B jet nebulization group. Comparison of the resistance [cmH(2)O/(L·s)] of the IFN-α jet nebulization group vs. the baseline group showed 2.56 (2.40, 2.68) vs. 2.26 (2.03, 2.40), P=0.037; of the IFN-α jet nebulization group vs. the blank group showed 2.56 (2.40, 2.68) vs. 2.11 (1.98, 2.27), P=0.003; of the IFN-α jet nebulization group vs. the normal saline group: 2.56 (2.40, 2.68) vs. 2.16 (2.08, 2.32), P=0.023; of the IFN-α jet nebulization group vs. the Combivent jet nebulization group: 2.56 (2.40, 2.68) vs. 2.18 (2.14, 2.27), P=0.018; and of the IFN-α jet nebulization group vs. the Amphotericin B jet nebulization group: 2.56 (2.40, 2.68) vs. 2.33 (2.05, 2.45), P=0.221. The effect of jet nebulization and vibrating mesh nebulization on the resistance of breathing filters showed no significant statistical difference. CONCLUSIONS: Jet nebulization with IFN-α significantly increased the resistance of the breathing filter within 24 hours and there was no significant difference in filter resistance between jet nebulization and vibrating mesh nebulization of IFN-α or Amphotericin B.

Genome association studies in human and genetic studies in mouse implicated members of the transmembrane protein 132 (TMEM132) family in multiple conditions including panic disorder, hearing loss, limb and kidney malformation. However, the presence of five TMEM132 paralogs in mammalian genomes makes it extremely challenging to reveal the full requirement for these proteins in vivo. In contrast, there is only one TMEM132 homolog, detonator (dtn), in the genome of fruit fly Drosophila melanogaster, enabling straightforward research into its in vivo function. In the current study, we generate multiple loss-of-function dtn mutant fly strains through a polycistronic tRNA-gRNA approach, and show that most embryos lacking both maternal and paternal dtn fail to hatch into larvae, indicating an essential role of dtn in Drosophila reproduction.

Dioscin, as a type of important natural steroidal saponin, has widespread sources, primarily from the fenugreek plant, which is an important raw material in the production of synthetic steroid hormone drugs. Dioscin has anti‑tumor, anti‑inflammatory, antioxidant and other significant pharmacological effects with high medicinal value. The present work aimed to research the protective effect and underlying mechanisms by which dioscin prevents acute lung injury (ALI). Mice were injected with 5 mg/kg LPS to induce lung injury. Mice were treated with dioscin (20, 40 and 60 mg/kg) following LPS‑induced lung injury. Treatment with dioscin significantly decreased total number of alveolar macrophages, water content of lung and total protein concentration in ALI mice. Dioscin treatment significantly suppressed the ALI‑induced interleukin (IL)‑1B, IL‑6, tumor necrosis factor‑α, nuclear factor (NF)‑κB, myeloperoxidase, interferon‑γ and intercellular adhesion molecule‑1 activities in ALI rats. Following this, the authors identified that dioscin significantly also suppressed cyclooxygenase‑2, heat shock protein 70, Toll‑like receptor 4, MyD88 and NF‑κB protein expression in ALI rats. The results suggested that dioscin prevents LPS‑induced ALI through inhibiting the TLR4/MyD88 signaling pathway via upregulation of HSP70.

The primary cilium plays critical roles in vertebrate development and physiology, but the mechanisms underlying its biogenesis remain poorly understood. We investigated the molecular function of C2 calcium-dependent domain containing 3 (C2cd3), an essential regulator of primary cilium biogenesis. We show that C2cd3 is localized to the centriolar satellites in a microtubule- and Pcm1-dependent manner; however, C2cd3 is dispensable for centriolar satellite integrity. C2cd3 is also localized to the distal ends of both mother and daughter centrioles and is required for the recruitment of five centriolar distal appendage proteins: Sclt1, Ccdc41, Cep89, Fbf1, and Cep164. Furthermore, loss of C2cd3 results in failure in the recruitment of Ttbk2 to the ciliary basal body as well as the removal of Cp110 from the ciliary basal body, two critical steps in initiating ciliogenesis. C2cd3 is also required for recruiting the intraflagellar transport proteins Ift88 and Ift52 to the mother centriole. Consistent with a role in distal appendage assembly, C2cd3 is essential for ciliary vesicle docking to the mother centriole. Our results suggest that C2cd3 regulates cilium biogenesis by promoting the assembly of centriolar distal appendages critical for docking ciliary vesicles and recruiting other essential ciliogenic proteins.

Hedgehog signaling is crucial for vertebrate development and physiology. Gli2, the primary effector of Hedgehog signaling, localizes to the tip of the primary cilium, but the importance of its ciliary localization remains unclear. We address the roles of Gli2 ciliary localization by replacing endogenous Gli2 with Gli2ΔCLR, a Gli2 variant not localizing to the cilium. The resulting Gli2ΔCLRKI and Gli2ΔCLRKI;Gli3 double mutants resemble Gli2-null and Gli2;Gli3 double mutants, respectively, suggesting the lack of Gli2ΔCLR activation in development. Significantly, Gli2ΔCLR cannot be activated either by pharmacochemical activation of Smo in vitro or by loss of Ptch1 in vivo. Finally, Gli2ΔCLR exhibits strong transcriptional activator activity in the absence of Sufu, suggesting that the lack of its activation in vivo results from a specific failure in relieving the inhibitory function of Sufu. Our results provide strong evidence that the ciliary localization of Gli2 is crucial for cilium-dependent activation of Hedgehog signaling.

Active repression of protein synthesis protects cells against protein malfolding during endoplasmic reticulum stress, nutrient deprivation and oxidative stress. However, long-term adaptation to these conditions requires synthesis of new stress-induced proteins. Phosphorylation of the alpha-subunit of translation initiation factor 2 (eIF2alpha) represses translation in diverse stressful conditions. GADD34 is a stress-inducible regulatory subunit of a holophosphatase complex that dephosphorylates eIF2alpha, and has been hypothesized to play a role in translational recovery. Here, we report that GADD34 expression correlated temporally with eIF2alpha dephosphorylation late in the stress response. Inactivation of both alleles of GADD34 prevented eIF2alpha dephosphorylation and blocked the recovery of protein synthesis, normally observed late in the stress response. Furthermore, defective recovery of protein synthesis markedly impaired translation of stress-induced proteins and interfered with programmed activation of stress-induced genes in the GADD34 mutant cells. These observations indicate that GADD34 controls a programmed shift from translational repression to stress-induced gene expression, and reconciles the apparent contradiction between the translational and transcriptional arms of cellular stress responses.

The unfolded protein response (UPR), caused by stress, matches the folding capacity of endoplasmic reticulum (ER) to the load of client proteins in the organelle. In yeast, processing of HAC1 mRNA by activated Ire1 leads to synthesis of the transcription factor Hac1 and activation of the UPR. The responses to activated IRE1 in metazoans are less well understood. Here we demonstrate that mutations in either ire-1 or the transcription-factor-encoding xbp-1 gene abolished the UPR in Caenorhabditis elegans. Mammalian XBP-1 is essential for immunoglobulin secretion and development of plasma cells, and high levels of XBP-1 messenger RNA are found in specialized secretory cells. Activation of the UPR causes IRE1-dependent splicing of a small intron from the XBP-1 mRNA both in C. elegans and mice. The protein encoded by the processed murine XBP-1 mRNA accumulated during the UPR, whereas the protein encoded by unprocessed mRNA did not. Purified mouse IRE1 accurately cleaved XBP-1 mRNA in vitro, indicating that XBP-1 mRNA is a direct target of IRE1 endonucleolytic activity. Our findings suggest that physiological ER load regulates a developmental decision in higher eukaryotes.

Phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 (eIF2alpha) on serine 51 integrates general translation repression with activation of stress-inducible genes such as ATF4, CHOP, and BiP in the unfolded protein response. We sought to identify new genes active in this phospho-eIF2alpha-dependent signaling pathway by screening a library of recombinant retroviruses for clones that inhibit the expression of a CHOP::GFP reporter. A retrovirus encoding the COOH terminus of growth arrest and DNA damage gene (GADD)34, also known as MYD116 (Fornace, A.J., D.W. Neibert, M.C. Hollander, J.D. Luethy, M. Papathanasiou, J. Fragoli, and N.J. Holbrook. 1989. Mol. Cell. Biol. 9:4196-4203; Lord K.A., B. Hoffman-Lieberman, and D.A. Lieberman. 1990. Nucleic Acid Res. 18:2823), was isolated and found to attenuate CHOP (also known as GADD153) activation by both protein malfolding in the endoplasmic reticulum, and amino acid deprivation. Despite normal activity of the cognate stress-inducible eIF2alpha kinases PERK (also known as PEK) and GCN2, phospho-eIF2alpha levels were markedly diminished in GADD34-overexpressing cells. GADD34 formed a complex with the catalytic subunit of protein phosphatase 1 (PP1c) that specifically promoted the dephosphorylation of eIF2alpha in vitro. Mutations that interfered with the interaction with PP1c prevented the dephosphorylation of eIF2alpha and blocked attenuation of CHOP by GADD34. Expression of GADD34 is stress dependent, and was absent in PERK(-)/- and GCN2(-)/- cells. These findings implicate GADD34-mediated dephosphorylation of eIF2alpha in a negative feedback loop that inhibits stress-induced gene expression, and that might promote recovery from translational inhibition in the unfolded protein response.

Protein kinases that phosphorylate the alpha subunit of eukaryotic initiation factor 2 (eIF2alpha) are activated in stressed cells and negatively regulate protein synthesis. Phenotypic analysis of targeted mutations in murine cells reveals a novel role for eIF2alpha kinases in regulating gene expression in the unfolded protein response (UPR) and in amino acid starved cells. When activated by their cognate upstream stress signals, the mammalian eIF2 kinases PERK and GCN2 repress translation of most mRNAs but selectively increase translation of Activating Transcription Factor 4 (ATF4), resulting in the induction of the downstream gene CHOP (GADD153). This is the first example of a mammalian signaling pathway homologous to the well studied yeast general control response in which eIF2alpha phosphorylation activates genes involved in amino acid biosynthesis. Mammalian cells thus utilize an ancient pathway to regulate gene expression in response to diverse stress signals.

The morphogen Sonic hedgehog, one of the Hedgehog (Hh) family of secreted proteins, plays a key role in patterning the mammalian spinal cord along its dorsoventral (D/V) axis through the activation of Glioma-associated oncogene (Gli) family of transcription factors. Suppressor of Fused (Sufu), a Gli-interacting protein, modulates the D/V patterning of the spinal cord by antagonizing Hh signaling. The molecular mechanisms underlying the function of Sufu in Hh pathway activation and spinal cord D/V patterning remain controversial, particularly in light of recent findings that Sufu protects Gli2 and Gli3 proteins from proteasomal degradation. In the current study, we show that Hh pathway activation and dorsal expansion of ventral spinal cord cell types in the absence of Sufu depend on the activator activities of all three Gli family proteins. We also show that Sufu plays a positive role in the maximal activation of Hh signaling that defines the ventral-most cell fate in the mammalian spinal cord, likely through protecting Gli2 and Gli3 proteins from degradation. Finally, by altering the level of Gli3 repressor on a background of reduced Gli activator activities, we reveal an important contribution of Gli3 repressor activity to the Hh pathway activation and the D/V patterning of the spinal cord.

Precise planar cell polarity (PCP) is critical for the development of multiple organ systems in animals. A group of core-PCP proteins are recognized to play crucial roles in convergent extension and other PCP-related processes in mammals. However, the functions of another group of PCP-regulating proteins, the PCP-effector proteins, are yet to be fully studied. In this study, the generation and characterization of a mouse mutant for the PCP effector gene Fuzzy (Fuz) is reported. Fuz homozygous mutants are embryonically lethal, with multiple defects including neural tube defects, abnormal dorsal/ventral patterning of the spinal cord, and defective anterior/posterior patterning of the limb buds. Fuz mutants also exhibit abnormal Hedgehog (Hh) signaling and inefficient proteolytic processing of Gli3. Finally, a significant decrease in cilia was found in Fuz homozygous mutants. In conclusion, Fuz plays an important role in cilia formation, Hh signal transduction, and embryonic development in mammals. Developmental Dynamics 238:3035–3042, 2009. © 2009 Wiley-Liss, Inc.

The Hedgehog (Hh) family of secreted proteins regulates mammalian development and cancer formation through Gli transcription factors, which exist in both activator and repressor forms. In vertebrates, the primary cilia play an essential role in Hh signal transduction and are required for both the activator and repressor activities of Gli proteins. In the current study, we demonstrate that mouse Suppressor of Fused (Sufu) interacts with Gli proteins and inhibits Gli activator activity in the absence of cilia. Removal of Sufu in both Smoothened (Smo) and Ift88 mutants, respectively, leads to full activation of Hh signaling, suggesting that Smo-mediated repression of Sufu, but not the inhibitory function of Sufu, requires cilia. Finally, we show that Sufu is important for proper activator/repressor ratio of Gli3 protein in mice, both in the presence and absence of cilia.

Cilia are essential for mammalian embryonic development as well as for the physiological activity of various adult organ systems. Despite the multiple crucial roles that cilia play, the mechanisms underlying ciliogenesis in mammals remain poorly understood. Taking a forward genetic approach, we have identified Hearty (Hty), a recessive lethal mouse mutant with multiple defects, including neural tube defects, abnormal dorsal-ventral patterning of the spinal cord, a defect in left-right axis determination and severe polydactyly (extra digits). By genetic mapping, sequence analysis of candidate genes and characterization of a second mutant allele, we identify Hty as C2cd3, a novel gene encoding a vertebrate-specific C2 domain-containing protein. Target gene expression and double-mutant analyses suggest that C2cd3 is an essential regulator of intracellular transduction of the Hedgehog signal. Furthering a link between Hedgehog signaling and cilia function, we find that cilia formation and proteolytic processing of Gli3 are disrupted in C2cd3 mutants. Finally, we observe C2cd3 protein at the basal body, consistent with its essential function in ciliogenesis. Interestingly, the human ortholog for this gene lies in proximity to the critical regions of Meckel-Gruber syndrome 2 (MKS2) and Joubert syndrome 2 (JBTS2), making it a potential candidate for these two human genetic disorders.

International audience; To insure an adequate supply of nutrients, omnivores choose among available food sources. This process is exemplified by the well-characterized innate aversion of omnivores to otherwise nutritious foods of imbalanced amino acid content. We report that brain-specific inactivation of GCN2, a ubiquitously expressed protein kinase that phosphorylates translation initiation factor 2 alpha (eIF2alpha) in response to intracellular amino acid deficiency, impairs this aversive response. GCN2 inactivation also diminishes phosphorylated eIF2alpha levels in the mouse anterior piriform cortex following consumption of an imbalanced meal. An ancient intracellular signal transduction pathway responsive to amino acid deficiency thus affects feeding behavior by activating a neuronal circuit that biases consumption against imbalanced food sources.

A two-step mass spectrometric method for characterization of phosphopeptides from peptide mixtures is presented. In the first step, phosphopeptide candidates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) based on their higher relative intensities in negative ion MALDI spectra than in positive ion MALDI spectra. The detection limit for this step was found to be 18 femtomoles or lower in the case of unfractionated in-solution digests of a model phosphoprotein, β-casein. In the second step, nanoelectrospray tandem mass (nES-MS/MS) spectra of doubly or triply charged precursor ions of these candidate phosphopeptides were obtained using a quadrupole time-of-flight (Q-TOF) mass spectrometer. This step provided information about the phosphorylated residues, and ruled out nonphosphorylated candidates, for these peptides. After [32P] labeling and reverse-phase high-performance liquid chromatography (RP-HPLC) to simplify the mixtures and to monitor the efficiency of phosphopeptide identification, we used this method to identify multiple autophosphorylation sites on the PKR-like endoplasmic reticulum kinase (PERK), a recently discovered mammalian stress-response protein. Copyright © 2001 John Wiley & Sons, Ltd.

The protein kinase PERK couples protein folding in the endoplasmic reticulum (ER) to polypeptide biosynthesis by phosphorylating the alpha subunit of eukaryotic translation initiation factor 2 (eIF2alpha), attenuating translation initiation in response to ER stress. PERK is highly expressed in mouse pancreas, an organ active in protein secretion. Under physiological conditions, PERK was partially activated, accounting for much of the phosphorylated eIF2alpha in the pancreas. The exocrine and endocrine pancreas developed normally in Perk-/- mice. Postnatally, ER distention and activation of the ER stress transducer IRE1alpha accompanied increased cell death and led to progressive diabetes mellitus and exocrine pancreatic insufficiency. These findings suggest a special role for translational control in protecting secretory cells from ER stress.

Malfolded proteins in the endoplasmic reticulum (ER) inhibit translation initiation. This response is believed to be mediated by increased phosphorylation of eukaryotic initiation factor 2alpha (eIF2alpha) and is hypothesized to reduce the work load imposed on the folding machinery during stress. Here we report that mutating the gene encoding the ER stress-activated eIF2alpha kinase PERK abolishes the phosphorylation of eIF2alpha in response to accumulation of malfolded proteins in the ER resulting in abnormally elevated protein synthesis and higher levels of ER stress. Mutant cells are markedly impaired in their ability to survive ER stress and inhibition of protein synthesis by cycloheximide treatment during ER stress ameliorates this impairment. PERK thus plays a major role in the ability of cells to adapt to ER stress.

Nature 415, 92–96 (2002). In this Letter, the commercial polyclonal antiserum used to detect endogenous XBP-1 was sc-7160 (Santa Cruz Biotechnology) and not sc-8015, as erroneously stated. The antibody sc-8015 is a mouse monoclonal and, in our hands, is not useful in detecting the endogenous proteinby immunoblotting.

The PCP effector gene Inturned regulates planar cell polarity (PCP) and wing hair formation in Drosophila wings. In order to understand the roles for Inturned in mammalian embryonic development, we generated a null mutant allele for the mouse homologue of Inturned (Intu) via gene-targeting in ES cells. Mouse Intu null mutants are homozygous lethal at midgestation, exhibiting multiple defects including neural tube closure defects, abnormal dorsal/ventral patterning of the central nervous system and abnormal anterior–posterior patterning of the limbs resulting in severe polydactyly (7–9 digits each limb). The developmental processes affected by the Intu mutation are under the control of Hh signaling through Gli-family transcription factors. We found that in Intu mutant embryos the expression of Gli1 and Ptch1, two direct transcriptional targets of Hh signaling, is down-regulated, and the proteolytic processing of Gli3 is compromised. We further demonstrate that Intu plays significant roles in the formation of primary cilia both during embryonic development and in cultured fibroblasts. Finally, a cytoplasmic GFP-Intu fusion protein efficiently rescues the ciliogenic defects in Intu mutant cells. In conclusion, we show that PCP effector gene Intu is an important regulator of cilia formation, Hh signal transduction, and embryonic development in mammals.

> Dans la nature, le comportement des animaux est dicte en partie par la recherche d’aliments susceptibles d’apporter les nutriments essentiels au fonctionnement de leur organisme. Cette selection de la nourriture est particulierement remarquable chez les omnivores, qui ont la capacite d’utiliser des sources diverses pour maintenir un statut nutritionnel equilibre. Outre des facteurs culturels et d’apprentissage, des facteurs innes interviennent egalement dans la selection de la nourriture. Par exemple, lorsqu’ils sont soumis a un regime alimentaire unique depourvu d’un acide amine indispensable (non synthetise par l’organisme dans des conditions physiologiques normales), les omnivores sont capables de detecter cette carence et de developper une aversion alimentaire qui consiste a rejeter ce regime considere comme nocif. Au cours de l’evolution, la capacite de refuser un aliment desequilibre en acides amines procure un avantage selectif a l’animal en lui permettant de privilegier une nourriture equilibree et mieux adaptee a ses besoins. Cette composante innee implique des mecanismes de detection des desequilibres alimentaires en acides amines permettant de declencher la reponse comportementale. Des travaux anciens ont implique le cerveau, et plus particulierement une zone appelee cortex piriforme anterieur (APC), dans la mise en place de l’aversion visa-vis de regimes desequilibres en aciNOUVELLE