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1.
FEBS J ; 291(7): 1483-1505, 2024 Apr.
Article En | MEDLINE | ID: mdl-38143314

Alterations in glycosylation are associated with breast tumor formation and progression. Nevertheless, the specific functions and mechanisms of the human major UDP-galactose transporter-encoding gene solute carrier family 35 member A2 (SLC35A2) in breast invasive carcinoma (BRCA) have not been fully determined. Here, we report that SLC35A2 promotes BRCA progression by activating extracellular signal regulated kinase (ERK). SLC35A2 expression and prognosis-predictive significance in pan-cancer were evaluated using public databases. The upstream non-coding RNAs (ncRNAs) of SLC35A2 were analyzed, and their expression and regulations were validated in breast tissues and cell lines by a quantitative PCR and dual-luciferase assays. We used bioinformatic tools to assess the link between SLC35A2 expression and immune infiltration and performed immunohistochemistry for validation. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, transwell, flow cytometer and western blotting were used to assess the proliferation, motility, cell cycle and apoptosis of BRCA cells in vitro. The xenograft models were constructed to assess the effect of SLC35A2 on BRCA tumor growth in vivo. The results indicated that SLC35A2 expression was upregulated and linked to an unfavorable prognosis in BRCA. The most likely upstream ncRNA-associated pathway of SLC35A2 in BRCA was the AC074117.1/hsa-let-7b-5p axis. SLC35A2 expression had positive correlations with the presence of Th2 cells, regulatory T cells and immune checkpoints. Knockdown of SLC35A2 could reduce BRCA cell proliferation, motility, and cause G2/M arrest and cell apoptosis via ERK signaling. Moreover, ERK activation can rescue the inhibitory effects of knockdown SLC35A2 in BRCA. In conclusion, AC074117.1/hsa-let-7b-5p axis-mediated high expression of SLC35A2 acts as a tumor promoter in BRCA via ERK signaling, which provides a potential target for BRCA treatment.


Breast Neoplasms , MicroRNAs , Humans , Female , Breast Neoplasms/pathology , Extracellular Signal-Regulated MAP Kinases , MAP Kinase Signaling System/genetics , Apoptosis/genetics , Cell Line, Tumor , G2 Phase Cell Cycle Checkpoints , Cell Proliferation/genetics , MicroRNAs/genetics , MicroRNAs/metabolism
2.
Ann Clin Lab Sci ; 53(5): 701-711, 2023 Sep.
Article En | MEDLINE | ID: mdl-37945022

OBJECTIVE: Kidney renal papillary cell carcinoma (KIRP) is the main subtype of renal cell carcinoma (RCC). The Progestin and AdipoQ Receptor Family Member 4 (PAQR4) has been found highly expressed in numerous cancers compared to normal tissues, but the role of PAQR4 in KIRP is unclear. METHODS: The expression levels of PAQR4 mRNA obtained from TCGA. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value of PAQR4 expression in KIRP patients. Chi-square test was used to determine the correlation between clinical features and PAQR4 expression. Kaplan-Meier analysis and Cox analysis were used to determine the prognostic value of expression levels of PAQR4 in KIRP patients. Gene set enrichment analysis (GSEA) was also performed. The level of PAQR4 mRNA, protein expression and cell proliferation were analyzed through qRT-PCR, western blot and CCK-8 assay. RESULTS: The expression levels of PAQR4 was significantly higher in KIRP tissues. Highly expressed PAQR4 mRNA was correlated with gender, clinical stage and overall survival. Multivariate analysis indicated that PAQR4 was an independent risk factor for patients with KIRP. GPCR ligand binding, signaling by Rho GTPases, DNA repair and PI3K-AKT signaling pathway were associated with aberrant PAQR4 expressions. Moreover, the expression levels of PAQR4 was upregulated in human KIRP and the inhibition of PAQR4 reduced cells proliferation. CONCLUSION: PAQR4 could be a potential diagnostic and prognostic biomarker in KIRP. The aberrant expression of this protein may trigger the alterations in the numerous signaling pathways, a process likely causing and accelerating the disease.


Carcinoma, Renal Cell , Kidney Neoplasms , Humans , Carcinoma, Renal Cell/metabolism , Kidney/pathology , Kidney Neoplasms/pathology , Ligands , Phosphatidylinositol 3-Kinases , Prognosis , Receptors, G-Protein-Coupled , RNA, Messenger/genetics
3.
Front Immunol ; 14: 1198551, 2023.
Article En | MEDLINE | ID: mdl-37398674

The fundamental principle of immune checkpoint blockade (ICB) is to protect tumor-infiltrating T cells from being exhausted. Despite the remarkable success achieved by ICB treatment, only a small group of patients benefit from it. Characterized by a hypofunctional state with the expression of multiple inhibitory receptors, exhausted T (Tex) cells are a major obstacle in improving ICB. T cell exhaustion is a progressive process which adapts to persistent antigen stimulation in chronic infections and cancers. In this review, we elucidate the heterogeneity of Tex cells and offer new insights into the hierarchical transcriptional regulation of T cell exhaustion. Factors and signaling pathways that induce and promote exhaustion are also summarized. Moreover, we review the epigenetic and metabolic alterations of Tex cells and discuss how PD-1 signaling affects the balance between T cell activation and exhaustion, aiming to provide more therapeutic targets for applications of combinational immunotherapies.


Immune Checkpoint Inhibitors , Neoplasms , Humans , Immune Checkpoint Inhibitors/pharmacology , Immune Checkpoint Inhibitors/therapeutic use , Gene Regulatory Networks , T-Cell Exhaustion , T-Lymphocytes , Gene Expression Regulation , Neoplasms/genetics , Neoplasms/therapy
4.
Neurobiol Dis ; 184: 106232, 2023 08.
Article En | MEDLINE | ID: mdl-37479091

Neurotransmission signaling is a highly conserved system attributed to various regulatory events. The excitatory and inhibitory neurotransmitter systems have been extensively studied, and their role in neuronal cell proliferation, synaptogenesis and dendrite formation in the adult brain is well established. Recent research has shown that epigenetic regulation plays a crucial role in mediating the expression of key genes associated with neurotransmitter pathways, including neurotransmitter receptor and transporter genes. The dysregulation of these genes has been linked to a range of neurological disorders such as attention-deficit/hyperactivity disorder, Parkinson's disease and schizophrenia. This article focuses on epigenetic regulatory mechanisms that control the expression of genes associated with four major chemical carriers in the brain: dopamine (DA), Gamma-aminobutyric acid (GABA), glutamate and serotonin. Additionally, we explore how aberrant epigenetic regulation of these genes can contribute to the pathogenesis of relevant neurological disorders. By targeting the epigenetic mechanisms that control neurotransmitter gene expression, there is a promising opportunity to advance the development of more effective treatments for neurological disorders with the potential to significantly improve the quality of life of individuals impacted by these conditions.


Epigenesis, Genetic , Nervous System Diseases , Humans , Quality of Life , Nervous System Diseases/genetics , Signal Transduction/genetics , Neurotransmitter Agents/metabolism
5.
BMC Med Educ ; 23(1): 391, 2023 May 27.
Article En | MEDLINE | ID: mdl-37245007

BACKGROUND: The error-proneness in the preanalytical and postanalytical stages is higher than that in the analytical stage of the total testing process. However, preanalytical and postanalytical quality management has not received enough attention in medical laboratory education and tests in clinical biochemistry courses. METHODS/APPROACH: Clinical biochemistry teaching program aim to improve students' awareness and ability of quality management according to international organization for standardization 15,189 requirements. We designed a student-centred laboratory training program, according to case-based learning that included 4 stages: "establish an overall testing process based on the patient's clinical indicator, clarify principles, improve operational skills, and review process and continuous improvement". The program was implemented in our college during the winter semesters of 2019 and 2020. A total of 185 undergraduate students majoring in medical laboratory science participated in the program as a test group, and the other 172 students were set up as the control group and adopted the conventional method. The participants were asked to finish an online survey to evaluate the class at the end. RESULTS/OUTCOMES: The test group had significantly better examination scores not only in experimental operational skills (89.27 ± 7.16 vs. 77.51 ± 4.72, p < 0.05 in 2019 grade, 90.31 ± 5.35 vs. 72.87 ± 8.41 in 2020 grade) but also in total examination (83.47 ± 6.16 vs. 68.90 ± 5.86 in 2019 grade, 82.42 ± 5.72 vs. 69.55 ± 7.54 in 2020 grade) than the control group. The results of the questionnaire survey revealed that the students in the test group better achieved classroom goals than those in the control group (all p < 0.05). CONCLUSIONS: The new student-centred laboratory training program based on case-based learning in clinical biochemistry is an effective and acceptable strategy compared with the conventional training program.


Education, Medical , Students, Medical , Humans , Students , Biochemistry/education , Educational Status , Clinical Competence , Teaching
6.
Viruses ; 14(12)2022 12 17.
Article En | MEDLINE | ID: mdl-36560820

Tomato is an important vegetable in the United States and around the world. Recently, tomato brown rugose fruit virus (ToBRFV), an emerging tobamovirus, has impacted tomato crops worldwide and can result in fruit loss. ToBRFV causes severe symptoms, such as mosaic, puckering, and necrotic lesions on leaves; other symptoms include brown rugose and marbling on fruits. More importantly, ToBRFV can overcome resistance in tomato cultivars carrying the Tm-22 locus. In this study, we recovered ToBRFV sequences from tomato seeds, leaves, and fruits from the U.S., Mexico, and Peru. Samples were pre-screened using a real-time RT-PCR assay prior to high-throughput sequencing. Virus draft genomes from 22 samples were assembled and analyzed against more than 120 publicly available genomes. Overall, most sequenced isolates were similar to each other and did not form a distinct population. Phylogenetic analysis revealed three clades within the ToBRFV population. Most of the isolates (95%) clustered in clade 3. Genetic analysis revealed differentiation between the three clades indicating minor divergence occurring. Overall, pairwise identity showed limited genetic diversity among the isolates in this study with worldwide isolates, with a pairwise identity ranging from 99.36% and 99.97%. The overall population is undergoing high gene flow and population expansion with strong negative selection pressure at all ToBRFV genes. Based on the results of this study, it is likely that the limited ToBRFV diversity is associated with the rapid movement and eradication of ToBRFV-infected material between countries.


Solanum lycopersicum , Tobamovirus , Fruit , Phylogeny , Tobamovirus/genetics , Genetic Variation
7.
Front Neurol ; 13: 948877, 2022.
Article En | MEDLINE | ID: mdl-36105777

Introduction: TRIO and CNKSR2 have been demonstrated as the important regulators of RAC1. TRIO is a guanine exchange factor (GEF) and promotes RAC1 activity by accelerating the GDP to GTP exchange. CNKSR2 is a scaffold and adaptor protein and helps to maintain Rac1 GTP/GDP levels at a concentration conducive for dendritic spines formation. Dysregulated RAC1 activity causes synaptic function defects leading to neurodevelopmental disorders (NDDs), which manifest as intellectual disability, learning difficulties, and language disorders. Case presentation: Here, we reported two cases with TRIO variation from one family and three cases with CNKSR2 variation from another family. The family with TRIO variation carries a novel heterozygous frameshift variant c.3506delG (p. Gly1169AlafsTer11), where a prenatal case and an apparently asymptomatic carrier mother with only enlarged left lateral ventricles were firstly reported. On the other hand, the CNKSR2 family carries a novel hemizygous non-sense variant c.1282C>T (p. Arg428*). Concurrently, we identified a novel phenotype never reported in known pathogenic CNKSR2 variants, that hydrocephalus and widening lateral ventricle in a 6-year-old male of this family. Furthermore, the genotype-phenotype relationship for TRIO, CNKSR2, and RAC1 was explored through a literature review. Conclusion: The novel variants and unique clinical features of these two pedigrees will help expand our understanding of the genetic and phenotypic profile of TRIO- and CNKSR2-related diseases.

8.
Cancers (Basel) ; 14(18)2022 Sep 10.
Article En | MEDLINE | ID: mdl-36139566

Mutations of spliceosome genes have been frequently identified in myeloid malignancies with the large-scale application of advanced sequencing technology. U2 small nuclear RNA auxiliary factor 1 (U2AF1), an essential component of U2AF heterodimer, plays a pivotal role in the pre-mRNA splicing processes to generate functional mRNAs. Over the past few decades, the mutation landscape of U2AF1 (most frequently involved S34 and Q157 hotspots) has been drawn in multiple cancers, particularly in myeloid malignancies. As a recognized early driver of myelodysplastic syndromes (MDSs), U2AF1 mutates most frequently in MDS, followed by acute myeloid leukemia (AML) and myeloproliferative neoplasms (MPNs). Here, for the first time, we summarize the research progress of U2AF1 mutations in myeloid malignancies, including the correlations between U2AF1 mutations with clinical and genetic characteristics, prognosis, and the leukemic transformation of patients. We also summarize the adverse effects of U2AF1 mutations on hematopoietic function, and the alterations in downstream alternative gene splicing and biological pathways, thus providing comprehensive insights into the roles of U2AF1 mutations in the myeloid malignancy pathogenesis. U2AF1 mutations are expected to be potential novel molecular markers for myeloid malignancies, especially for risk stratification, prognosis assessment, and a therapeutic target of MDS patients.

9.
Front Immunol ; 13: 839291, 2022.
Article En | MEDLINE | ID: mdl-35935968

RNA, one of the major building blocks of the cell, participates in many essential life processes. RNA stability is well-established to be closely related to various RNA modifications. To date, hundreds of different RNA modifications have been identified. N6-methyladenosine (m6A) is one of the most important RNA modifications in mammalian cells. An increasing body of evidence from recently published studies suggests that m6A modification is a novel immune system regulator of the generation and differentiation of hematopoietic stem cells (HSCs) and immune cells. In this review, we introduce the process and relevant regulatory mechanisms of m6A modification; summarize recent findings of m6A in controlling HSC generation and self-renewal, and the development and differentiation of T and B lymphocytes from HSCs; and discuss the potential mechanisms involved.


Hematopoietic Stem Cells , RNA , Adenosine/genetics , Animals , B-Lymphocytes , Cell Differentiation/genetics , Mammals/genetics , RNA/genetics
10.
Immun Inflamm Dis ; 10(7): e644, 2022 07.
Article En | MEDLINE | ID: mdl-35759243

Chromodomain helicase DNA binding protein 4 (CHD4) is an ATPase subunit of the nucleosome remodeling and deacetylation complex. It has been implicated in gene transcription, DNA damage repair, maintenance of genome stability, and chromatin assembly. Meanwhile, it is highly related to cell cycle progression and the proceeding of malignancy. Most of the previous studies were focused on the function of CHD4 with tumor cells, cancer stem cells, and cancer cells multidrug resistance. Recently, some researchers have explored the CHD4 functions on the development and differentiation of adaptive immune cells, such as T and B lymphocytes. In this review, we will discuss details of CHD4 in lymphocyte differentiation and development, as well as the critical role of CHD4 in the pathogenesis of the autoimmune disease.


Autoimmune Diseases , Chromatin Assembly and Disassembly , B-Lymphocytes/metabolism , Cell Differentiation , Humans , Mi-2 Nucleosome Remodeling and Deacetylase Complex/genetics , Mi-2 Nucleosome Remodeling and Deacetylase Complex/metabolism , Nucleosomes , T-Lymphocytes
12.
Sci Rep ; 11(1): 8529, 2021 04 20.
Article En | MEDLINE | ID: mdl-33879822

This study aimed to determine the levels of health-related behaviours (physical activity, screen exposure and sleep status) among Chinese students from primary, secondary and high schools during the pandemic of COVID-19, as well as their changes compared with their status before the pandemic. A cross-sectional online survey of 10,933 students was conducted among 10 schools in Guangzhou, China, between 8th and 15th March, 2020. After getting the informed consent from student's caregivers, an online questionnaire was designed and used to obtain time spending on health-related behaviours during the pandemic of COVID-19, as well as the changes compared with 3 months before the pandemic, which was completed by students themselves or their caregivers. Students were stratified by regions (urban, suburban, exurban), gender (boys and girls), and grades (lower grades of primary school, higher grades of primary schools, secondary schools and high schools). Data were expressed as number and percentages and Chi-square test was used to analyse difference between groups. Overall, the response rate of questionnaire was 95.3% (10,416/10,933). The median age of included students was 13.0 (10.0, 16.0) years and 50.1% (n = 5,219) were boys. 41.4%, 53.6% and 53.7% of total students reported less than 15 min per day in light, moderate and vigorous activities and 58.7% (n = 6,113) reported decreased participation in physical activity compared with the time before pandemic. Over 5 h of screen time spending on online study was reported by 44.6% (n = 4,649) of respondents, particular among high school students (81.0%). 76.9% of students reported increased screen time compared with the time before pandemic. Inadequate sleep was identified among 38.5% of students and the proportion was highest in high school students (56.9%). Our study indicated that, during the COVID-19 pandemic, the school closure exerted tremendous negative effects on school-aged children's health habits, including less physical activity, longer screen exposure and irregular sleeping pattern.


COVID-19/epidemiology , Exercise/psychology , Screen Time , Sleep Deprivation/epidemiology , Students/psychology , Adolescent , COVID-19/psychology , Child , China/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Pandemics , Surveys and Questionnaires
13.
Plant Dis ; 104(4): 1009-1010, 2020 Apr.
Article En | MEDLINE | ID: mdl-32065562

'Candidatus Phytoplasma pini'-related strain MDPP, the reference strain of subgroup 16SrXXI-B, is a pathogen associated with witches' broom disease of Pinus spp. in North America. Here, we report the first draft genome sequence of 'Ca. Phytoplasma pini' strain MDPP, which consists of 474,136 bases, with a G + C content of 22.22%. This information will facilitate comparative genomics of gymnosperm-infecting phytoplasmas.


Cycadopsida , Phytoplasma , DNA, Bacterial , Genomics , North America , Phylogeny , Plant Diseases , Pyrrolidines , RNA, Ribosomal, 16S
14.
Plant Dis ; 104(3): 627-629, 2020 Mar.
Article En | MEDLINE | ID: mdl-31910115

'Candidatus Liberibacter asiaticus' is the unculturable causative agent of citrus huanglongbing disease. Here, we report the first citrus root metagenome sequence containing the draft genome of 'Ca. L. asiaticus' strain AHCA17, obtained from a pummelo tree in California. The assembled genome was 1.2 Mbp and resulted in 37 contigs (N50 = 158.7 kbp) containing 1,057 predicted open reading frames and 45 RNA-coding genes. This draft genome will provide a valuable resource in further study of 'Ca. L. asiaticus' genome diversity and pathogen epidemiology.


Citrus , Rhizobiaceae , California , Plant Diseases
15.
Sci Rep ; 9(1): 18962, 2019 12 12.
Article En | MEDLINE | ID: mdl-31831765

Huanglongbing (HLB) is a worldwide deadly citrus disease caused by the phloem-limited bacteria 'Candidatus Liberibacter asiaticus' (CLas) vectored by Asian citrus psyllids. In order to effectively manage this disease, it is crucial to understand the relationship among the bacterial isolates from different geographical locations. Whole genome sequencing approaches will provide more precise molecular characterization of the diversity among populations. Due to the lack of in vitro culture, obtaining the whole genome sequence of CLas is still a challenge, especially for medium to low titer samples. Hundreds of millions of sequencing reads are needed to get good coverage of CLas from an HLB positive citrus sample. In order to overcome this limitation, we present here a new method, Agilent SureSelect XT HS target enrichment, which can specifically enrich CLas from a metagenomic sample while greatly reducing cost and increasing whole genome coverage of the pathogen. In this study, the CLas genome was successfully sequenced with 99.3% genome coverage and over 72X sequencing coverage from low titer tissue samples (equivalent to 28.52 Cq using Li 16 S qPCR). More importantly, this method also effectively captures regions of diversity in the CLas genome, which provides precise molecular characterization of different strains.


Genome, Bacterial , Rhizobiaceae/genetics , Whole Genome Sequencing , Rhizobiaceae/classification
16.
Nat Commun ; 10(1): 5343, 2019 11 25.
Article En | MEDLINE | ID: mdl-31767855

In flies, the chromosomal kinase JIL-1 is responsible for most interphase histone H3S10 phosphorylation and has been proposed to protect active chromatin from acquiring heterochromatic marks, such as dimethylated histone H3K9 (H3K9me2) and HP1. Here, we show that JIL-1's targeting to chromatin depends on a PWWP domain-containing protein JASPer (JIL-1 Anchoring and Stabilizing Protein). JASPer-JIL-1 (JJ)-complex is the major form of kinase in vivo and is targeted to active genes and telomeric transposons via binding of the PWWP domain of JASPer to H3K36me3 nucleosomes, to modulate transcriptional output. JIL-1 and JJ-complex depletion in cycling cells lead to small changes in H3K9me2 distribution at active genes and telomeric transposons. Finally, we identify interactors of the endogenous JJ-complex and propose that JIL-1 not only prevents heterochromatin formation but also coordinates chromatin-based regulation in the transcribed part of the genome.


Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Histones/metabolism , Protein Serine-Threonine Kinases/metabolism , Animals , Cell Line , Chromatin/genetics , Chromatin/metabolism , Chromatin Assembly and Disassembly/genetics , Drosophila Proteins/genetics , Drosophila melanogaster/cytology , Drosophila melanogaster/genetics , Heterochromatin/genetics , Heterochromatin/metabolism , Humans , Interphase , Methylation , Phosphorylation , Protein Processing, Post-Translational , Protein Serine-Threonine Kinases/genetics
17.
Am J Hum Biol ; 30(6): e23143, 2018 11.
Article En | MEDLINE | ID: mdl-30246426

OBJECTIVES: Although delayed parenthood has been linked to various adverse health outcomes in offspring, little attention has been given to the relationship between an increased parental age at childbirth and fat distribution in offspring. We aimed to determine the relationship between parental age at childbirth and body fat partitioning in Chinese children. METHODS: A total of 463 children (mean age, 8 years; 43% female) were recruited. Dual-energy X-ray absorptiometry was used to determine the fat mass (FM) and percentage of fat mass (%FM) in various areas of the body. Weight and height were measured. The body mass index (BMI) and fat mass index (FMI) were calculated. A questionnaire was used to collect information about parental variables and other confounders. RESULTS: Multiple linear regression analyses suggested that for each additional year of maternal age at delivery, the BMI, FMI, and FM at whole-body, trunk, android, gynoid, and appendicular region increased by 0.115 kg/m2 , 0.076 kg/m2 ; 128.4 g, 57.71 g, 10.96 g, 25.07 g, and 67.88 g, respectively, after adjusting for covariates (P = .002-.017). In the analysis of covariance, children of mothers aged ≥31 years exhibited higher BMI, FMI, total-body and segmental FM, compared to those of mothers aged ≤25 years (P-trend = 0.002-0.017). Similar tendencies were also observed for the %FM (P-trend = 0.002-0.017). However, there was no significant relationship between paternal age at childbirth and any of the body fat measures in children. CONCLUSIONS: An increasing maternal age at childbirth was associated with increased body fat accumulation in offspring, whereas paternal age at childbirth appeared to have no such association.


Body Fat Distribution/statistics & numerical data , Fathers/statistics & numerical data , Maternal Age , Mothers/statistics & numerical data , Paternal Age , Absorptiometry, Photon , Adult , Age Factors , Body Mass Index , Child , China , Female , Humans , Male , Parturition , Young Adult
18.
Development ; 144(18): 3232-3240, 2017 09 15.
Article En | MEDLINE | ID: mdl-28807902

A model has been proposed in which JIL-1 kinase-mediated H3S10 and H2Av phosphorylation is required for transcriptional elongation and heat shock-induced chromatin decondensation. However, here we show that although H3S10 phosphorylation is indeed compromised in the H2Av null mutant, chromatin decondensation at heat shock loci is unaffected in the absence of JIL-1 as well as of H2Av and that there is no discernable decrease in the elongating form of RNA polymerase II in either mutant. Furthermore, mRNA for the major heat shock protein Hsp70 is transcribed at robust levels in both H2Av and JIL-1 null mutants. Using a different chromatin remodeling paradigm that is JIL-1 dependent, we provide evidence that ectopic tethering of JIL-1 and subsequent H3S10 phosphorylation recruits PARP-1 to the remodeling site independently of H2Av phosphorylation. These data strongly suggest that H2Av or H3S10 phosphorylation by JIL-1 is not required for chromatin decondensation or transcriptional elongation in Drosophila.


Chromatin/metabolism , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Histones/metabolism , Phosphoserine/metabolism , Transcription Elongation, Genetic , Animals , Euchromatin/metabolism , Green Fluorescent Proteins/metabolism , Heat-Shock Response/genetics , Immunoblotting , Immunohistochemistry , Lac Operon/genetics , Mutation/genetics , Phosphorylation , Poly(ADP-ribose) Polymerases/metabolism , Polytene Chromosomes/metabolism , Protein Serine-Threonine Kinases/metabolism , Transgenes
19.
G3 (Bethesda) ; 6(12): 3859-3867, 2016 12 07.
Article En | MEDLINE | ID: mdl-27672113

TORC1 regulates metabolism and growth in response to a large array of upstream inputs. The evolutionarily conserved trimeric GATOR1 complex inhibits TORC1 activity in response to amino acid limitation. In humans, the GATOR1 complex has been implicated in a wide array of pathologies including cancer and hereditary forms of epilepsy. However, the precise role of GATOR1 in animal physiology remains largely undefined. Here, we characterize null mutants of the GATOR1 components nprl2, nprl3, and iml1 in Drosophila melanogaster We demonstrate that all three mutants have inappropriately high baseline levels of TORC1 activity and decreased adult viability. Consistent with increased TORC1 activity, GATOR1 mutants exhibit a cell autonomous increase in cell growth. Notably, escaper nprl2 and nprl3 mutant adults have a profound locomotion defect. In line with a nonautonomous role in the regulation of systemic metabolism, expressing the Nprl3 protein in the fat body, a nutrient storage organ, and hemocytes but not muscles and neurons rescues the motility of nprl3 mutants. Finally, we show that nprl2 and nprl3 mutants fail to activate autophagy in response to amino acid limitation and are extremely sensitive to both amino acid and complete starvation. Thus, in Drosophila, in addition to maintaining baseline levels of TORC1 activity, the GATOR1 complex has retained a critical role in the response to nutrient stress. In summary, the TORC1 inhibitor GATOR1 contributes to multiple aspects of the development and physiology of Drosophila.


Drosophila melanogaster/physiology , Energy Metabolism , Homeostasis , Multiprotein Complexes/metabolism , Stress, Physiological , Animals , Animals, Genetically Modified , Autophagy , CRISPR-Cas Systems , Cell Proliferation , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Female , Genes, Lethal , Locomotion , Mechanistic Target of Rapamycin Complex 1 , Protein Binding , RNA, Guide, Kinetoplastida , Sequence Deletion , TOR Serine-Threonine Kinases/metabolism
20.
PLoS Genet ; 12(5): e1006036, 2016 05.
Article En | MEDLINE | ID: mdl-27166823

TORC1 is a master regulator of metabolism in eukaryotes that responds to multiple upstream signaling pathways. The GATOR complex is a newly defined upstream regulator of TORC1 that contains two sub-complexes, GATOR1, which inhibits TORC1 activity in response to amino acid starvation and GATOR2, which opposes the activity of GATOR1. While the GATOR1 complex has been implicated in a wide array of human pathologies including cancer and hereditary forms of epilepsy, the in vivo relevance of the GATOR2 complex remains poorly understood in metazoans. Here we define the in vivo role of the GATOR2 component Wdr24 in Drosophila. Using a combination of genetic, biochemical, and cell biological techniques we demonstrate that Wdr24 has both TORC1 dependent and independent functions in the regulation of cellular metabolism. Through the characterization of a null allele, we show that Wdr24 is a critical effector of the GATOR2 complex that promotes the robust activation of TORC1 and cellular growth in a broad array of Drosophila tissues. Additionally, epistasis analysis between wdr24 and genes that encode components of the GATOR1 complex revealed that Wdr24 has a second critical function, the TORC1 independent regulation of lysosome dynamics and autophagic flux. Notably, we find that two additional members of the GATOR2 complex, Mio and Seh1, also have a TORC1 independent role in the regulation of lysosome function. These findings represent a surprising and previously unrecognized function of GATOR2 complex components in the regulation of lysosomes. Consistent with our findings in Drosophila, through the characterization of a wdr24-/- knockout HeLa cell line we determined that Wdr24 promotes lysosome acidification and autophagic flux in mammalian cells. Taken together our data support the model that Wdr24 is a key effector of the GATOR2 complex, required for both TORC1 activation and the TORC1 independent regulation of lysosomes.


Drosophila Proteins/genetics , Lysosomes/genetics , Multiprotein Complexes/genetics , Nuclear Proteins/genetics , Proteins/genetics , TOR Serine-Threonine Kinases/genetics , Animals , Cell Cycle Proteins , Drosophila Proteins/metabolism , Drosophila melanogaster , Epistasis, Genetic , Gene Knockout Techniques , HeLa Cells , Humans , Lysosomes/metabolism , Mechanistic Target of Rapamycin Complex 1 , Multiprotein Complexes/metabolism , Nuclear Proteins/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism
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