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1.
Mol Med ; 30(1): 124, 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39138413

ABSTRACT

BACKGROUND: Obesity is well-established as a significant contributor to the development of insulin resistance (IR) and diabetes, partially due to elevated plasma saturated free fatty acids like palmitic acid (PA). Grb10-interacting GYF Protein 2 (GIGYF2), an RNA-binding protein, is widely expressed in various tissues including the liver, and has been implicated in diabetes-induced cognitive impairment. Whereas, its role in obesity-related IR remains uninvestigated. METHODS: In this study, we employed palmitic acid (PA) exposure to establish an in vitro IR model in the human liver cancer cell line HepG2 with high-dose chronic PA treatment. The cells were stained with fluorescent dye 2-NBDG to evaluate cell glucose uptake. The mRNA expression levels of genes were determined by real-time qRT-PCR (RT-qPCR). Western blotting was employed to examine the protein expression levels. The RNA immunoprecipitation (RIP) was used to investigate the binding between protein and mRNA. Lentivirus-mediated gene knockdown and overexpression were employed for gene manipulation. In mice, an IR model induced by a high-fat diet (HFD) was established to validate the role and action mechanisms of GIGYF2 in the modulation of HFD-induced IR in vivo. RESULTS: In hepatocytes, high levels of PA exposure strongly trigger the occurrence of hepatic IR evidenced by reduced glucose uptake and elevated extracellular glucose content, which is remarkably accompanied by up-regulation of GIGYF2. Silencing GIGYF2 ameliorated PA-induced IR and enhanced glucose uptake. Conversely, GIGYF2 overexpression promoted IR, PTEN upregulation, and AKT inactivation. Additionally, PA-induced hepatic IR caused a notable increase in STAU1, which was prevented by depleting GIGYF2. Notably, silencing STAU1 prevented GIGYF2-induced PTEN upregulation, PI3K/AKT pathway inactivation, and IR. STAU1 was found to stabilize PTEN mRNA by binding to its 3'UTR. In liver cells, tocopherol treatment inhibits GIGYF2 expression and mitigates PA-induced IR. In the in vivo mice model, GIGYF2 knockdown and tocopherol administration alleviate high-fat diet (HFD)-induced glucose intolerance and IR, along with the suppression of STAU1/PTEN and restoration of PI3K/AKT signaling. CONCLUSIONS: Our study discloses that GIGYF2 mediates obesity-related IR by disrupting the PI3K/AKT signaling axis through the up-regulation of STAU1/PTEN. Targeting GIGYF2 may offer a potential strategy for treating obesity-related metabolic diseases, including type 2 diabetes.


Subject(s)
Carrier Proteins , Insulin Resistance , Liver , PTEN Phosphohydrolase , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , RNA-Binding Proteins , Signal Transduction , Humans , Proto-Oncogene Proteins c-akt/metabolism , Animals , PTEN Phosphohydrolase/metabolism , PTEN Phosphohydrolase/genetics , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/genetics , Phosphatidylinositol 3-Kinases/metabolism , Mice , Liver/metabolism , Carrier Proteins/metabolism , Carrier Proteins/genetics , Hep G2 Cells , Palmitic Acid , Male , Cytoskeletal Proteins/metabolism , Cytoskeletal Proteins/genetics , Mice, Inbred C57BL , Diet, High-Fat/adverse effects
2.
Discov Oncol ; 15(1): 157, 2024 May 11.
Article in English | MEDLINE | ID: mdl-38733530

ABSTRACT

OBJECTIVE: To investigate the action of circPDK1 in paclitaxel (PTX) resistance in non-small cell lung cancer (NSCLC). METHODS: circPDK1, miR-4731-5p, and GIGYF1 levels were determined by RT-qPCR and Western blot. Cell proliferation was detected by CCK-8 and colony formation assay, apoptosis by flow cytometry, invasion by Transwell assay. The targeting relationship between miR-4731-5p and circPDK1 or GIGYF1 was confirmed by dual luciferase reporter gene and RIP assay. A xenograft tumor model was established to determine the role of circPDK1 in PTX resistance. RESULTS: circPDK1 was overexpressed in PTX-resistant NSCLC, and depleting circPDK1 hampered proliferation and invasion of PTX-resistant cells, activated apoptosis, and improved PTX sensitivity. circPDK1 bound to miR-4731-5p, and increasing miR-4731-5p expression salvaged the effect of circPDK1 depletion on PTX resistance. miR-4731-5p directly targeted GIGYF1, and upregulating GIGYF1 offset the promoting effect of circPDK1 knockdown on PTX sensitivity. NSCLC tumor growth was inhibited and PTX sensitivity improved when circPDK1 was suppressed. CONCLUSION: Depleting circPDK1 promotes PTX sensitivity of NSCLC cells via miR-4731-5p/GIGYF1 axis, thereby inhibiting NSCLC pregnancy.

3.
J Cell Sci ; 136(19)2023 10 01.
Article in English | MEDLINE | ID: mdl-37732428

ABSTRACT

Viruses use microRNAs (miRNAs) to impair the host antiviral response and facilitate viral infection by expressing their own miRNAs or co-opting cellular miRNAs. miRNAs inhibit translation initiation of their target mRNAs by recruiting the GIGYF2-4EHP (or EIF4E2) translation repressor complex to the mRNA 5'-cap structure. We recently reported that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-encoded non-structural protein 2 (NSP2) interacts with GIGYF2. This interaction is critical for blocking translation of the Ifnb1 mRNA that encodes the cytokine interferon ß, and thereby impairs the host antiviral response. However, it is not known whether NSP2 also affects miRNA-mediated silencing. Here, we demonstrate the pervasive augmentation of miRNA-mediated translational repression of cellular mRNAs by NSP2. We show that NSP2 interacts with argonaute 2 (AGO2), the core component of the miRNA-induced silencing complex (miRISC), via GIGYF2 and enhances the translational repression mediated by natural miRNA-binding sites in the 3' untranslated region of cellular mRNAs. Our data reveal an additional layer of the complex mechanism by which SARS-CoV-2 and likely other coronaviruses manipulate the host gene expression program by co-opting the host miRNA-mediated silencing machinery.


Subject(s)
COVID-19 , MicroRNAs , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , COVID-19/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Antiviral Agents
4.
Arthritis Res Ther ; 25(1): 175, 2023 09 20.
Article in English | MEDLINE | ID: mdl-37730603

ABSTRACT

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare complication of primary Sjögren's syndrome (pSS). Several genes have proven to be associated with pSS and PAH. However, there is no study specifically addressing the genetic susceptibility in pSS combined with PAH. METHODS: Thirty-four unrelated patients with pSS-PAH were recruited from April 2019 to July 2021 at Peking Union Medical College Hospital. Demographic and clinical data were recorded in detail, and peripheral blood samples were collected for whole-exome sequencing (WES). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to predict the functional effect of mutant genes. Genetic variants identified by WES were confirmed by polymerase chain reaction (PCR)-Sanger sequencing. RESULTS: We totally identified 141 pathogenic variant loci of 129 genes in these 34 pSS-PAH patients, using WES analysis. Patients with a family history of rheumatic diseases are more likely to carry FLG mutations or carry gene variations related to the biosynthesis of the amino acids pathway (p < 0.05). According to Sanger sequencing confirmation and pathogenicity validation, we totally identified five candidate pathogenic variants including FLG c.12064A > T, BCR c.3275_3278dupCCGG, GIGYF2 c.3463C > A, ITK c.1741C > T, and SLC26A4 c.919-2A > G. CONCLUSION: Our findings provide preliminary data of exome sequencing to identify susceptibility loci for pSS-PAH and enriched our understanding of the genetic etiology for pSS-PAH. The candidate pathogenic genes may be the potential genetic markers for early warning of this disease.


Subject(s)
Hypertension, Pulmonary , Pulmonary Arterial Hypertension , Sjogren's Syndrome , Humans , Exome Sequencing , Sjogren's Syndrome/complications , Sjogren's Syndrome/genetics , Amino Acids
5.
Int J Med Sci ; 20(8): 1038-1045, 2023.
Article in English | MEDLINE | ID: mdl-37484805

ABSTRACT

GRB10 interacting GYF protein 1 (GIGYF1) binds to the N-terminal region of Grb10, regulates multiple signaling pathways. However, it is not clear what happens to cell proliferation, metastasis, apoptosis, and autophagy when the expression level of GIGYF1 gene is reduced. Detection of GIGYF1 expression in clinical tissue specimens and gastric cancer (GC) cell lines by quantitative Real-time PCR (qRT-PCR), GIGYF1 gene was knocked down in MGC-803 cells using small interfering RNA, the effect of GIGYF1 gene on cell metastasis was detected using Transwell assay and wound healing assay, the effect on cell proliferation was detected using plate cloning assay and cck-8 assay, the effect on apoptosis was detected using flow cytometry, autophagosomes were detected using laser confocal microscopy, and the effect on protein expression was detected using immunofluorescence and Western blotting. GIGYF1 gene expression was higher in tumor tissue samples than in paracancer tissue samples, and higher in human GC cell lines than in human normal gastric epithelial cells. GIGYF1 gene knockdown inhibited cell migration, scratch healing ability and EMT process, weakened cell proliferation ability, increased apoptosis rate, promoted the formation of autophagosomes, and changed the corresponding protein expression level. Meanwhile, GIGYF1 knockdowns inhibited the ERK and AKT signaling. In conclusion, the low expression of GIGYF1 gene can inhibit the occurrence and progression of gastric cancer, during which the ERK and AKT signaling pathways are inhibited.


Subject(s)
Stomach Neoplasms , Humans , Stomach Neoplasms/pathology , Proto-Oncogene Proteins c-akt/metabolism , Cell Proliferation/genetics , Autophagy/genetics , Apoptosis/genetics , Cell Line, Tumor , Cell Movement/genetics , Gene Expression Regulation, Neoplastic , Carrier Proteins/genetics , Carrier Proteins/metabolism
6.
Biol Psychiatry ; 94(10): 769-779, 2023 11 15.
Article in English | MEDLINE | ID: mdl-36924980

ABSTRACT

BACKGROUND: Autism spectrum disorder is characterized by deficits in social communication and restricted or repetitive behaviors. Due to the extremely high genetic and phenotypic heterogeneity, it is critical to pinpoint the genetic factors for understanding the pathology of these disorders. METHODS: We analyzed the exomes generated by the SPARK (Simons Powering Autism Research) project and performed a meta-analysis with previous data. We then generated 1 zebrafish knockout model and 3 mouse knockout models to examine the function of GIGYF1 in neurodevelopment and behavior. Finally, we performed whole tissue and single-nucleus transcriptome analysis to explore the molecular and cellular function of GIGYF1. RESULTS: GIGYF1 variants are significantly associated with various neurodevelopmental disorder phenotypes, including autism, global developmental delay, intellectual disability, and sleep disturbance. Loss of GIGYF1 causes similar behavioral effects in zebrafish and mice, including elevated levels of anxiety and reduced social engagement, which is reminiscent of the behavioral deficits in human patients carrying GIGYF1 variants. Moreover, excitatory neuron-specific Gigyf1 knockout mice recapitulate the increased repetitive behaviors and impaired social memory, suggesting a crucial role of Gigyf1 in excitatory neurons, which correlates with the observations in single-nucleus RNA sequencing. We also identified a series of downstream target genes of GIGYF1 that affect many aspects of the nervous system, especially synaptic transmission. CONCLUSIONS: De novo variants of GIGYF1 are associated with neurodevelopmental disorders, including autism spectrum disorder. GIGYF1 is involved in neurodevelopment and animal behavior, potentially through regulating hippocampal CA2 neuronal numbers and disturbing synaptic transmission.


Subject(s)
Autism Spectrum Disorder , Carrier Proteins , Animals , Humans , Mice , Autism Spectrum Disorder/genetics , Autistic Disorder/genetics , Behavior, Animal/physiology , Carrier Proteins/genetics , Disease Models, Animal , Memory Disorders/genetics , Mice, Knockout/genetics , Zebrafish/genetics
7.
FEBS J ; 290(2): 266-285, 2023 01.
Article in English | MEDLINE | ID: mdl-34758096

ABSTRACT

The cap-binding protein 4EHP/eIF4E2 has been a recent object of interest in the field of post-transcriptional gene regulation and translational control. From ribosome-associated quality control, to RNA decay and microRNA-mediated gene silencing, this member of the eIF4E protein family regulates gene expression through numerous pathways. Low in abundance but ubiquitously expressed, 4EHP interacts with different binding partners to form multiple protein complexes that regulate translation in a variety of biological contexts. Documented functions of 4EHP primarily relate to its role as a translational repressor, but recent findings indicate that it might also participate in the activation of translation in specific settings. In this review, we discuss the known functions, properties and mechanisms that involve 4EHP in the control of gene expression. We also discuss our current understanding of how 4EHP processes are regulated in eukaryotic cells, and the diseases implicated with dysregulation of 4EHP-mediated translational control.


Subject(s)
Eukaryotic Initiation Factor-4E , MicroRNAs , RNA Cap-Binding Proteins/chemistry , RNA Cap-Binding Proteins/genetics , RNA Cap-Binding Proteins/metabolism , Eukaryotic Initiation Factor-4E/genetics , Eukaryotic Initiation Factor-4E/metabolism , MicroRNAs/metabolism , Gene Expression Regulation , Protein Biosynthesis , Protein Binding
8.
Cell Rep ; 41(4): 111536, 2022 10 25.
Article in English | MEDLINE | ID: mdl-36288698

ABSTRACT

The "last resort" pathway results in ubiquitylation and degradation of RNA polymerase II in response to transcription stress and is governed by factors such as Def1 in yeast. Here, we show that the SMY2 gene acts as a multi-copy suppressor of DEF1 deletion and functions at multiple steps of the last resort pathway. We also provide genetic and biochemical evidence from disparate cellular processes that Smy2 works more broadly as a hitherto overlooked regulator of Cdc48 function. Similarly, the Smy2 homologs GIGYF1 and -2 affect the transcription stress response in human cells and regulate the function of the Cdc48 homolog VCP/p97, presently being explored as a target for cancer therapy. Indeed, we show that the apoptosis-inducing effect of VCP inhibitors NMS-873 and CB-5083 is GIGYF1/2 dependent.


Subject(s)
Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae , Humans , Adenosine Triphosphatases/metabolism , Carrier Proteins/genetics , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , RNA Polymerase II/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Valosin Containing Protein/genetics , Valosin Containing Protein/metabolism
9.
Proc Natl Acad Sci U S A ; 119(32): e2204539119, 2022 08 09.
Article in English | MEDLINE | ID: mdl-35878012

ABSTRACT

Viruses evade the innate immune response by suppressing the production or activity of cytokines such as type I interferons (IFNs). Here we report the discovery of a mechanism by which the SARS-CoV-2 virus coopts an intrinsic cellular machinery to suppress the production of the key immunostimulatory cytokine IFN-ß. We reveal that the SARS-CoV-2 encoded nonstructural protein 2 (NSP2) directly interacts with the cellular GIGYF2 protein. This interaction enhances the binding of GIGYF2 to the mRNA cap-binding protein 4EHP, thereby repressing the translation of the Ifnb1 mRNA. Depletion of GIGYF2 or 4EHP significantly enhances IFN-ß production, which inhibits SARS-CoV-2 replication. Our findings reveal a target for rescuing the antiviral innate immune response to SARS-CoV-2 and other RNA viruses.


Subject(s)
COVID-19 , Carrier Proteins , Interferon Type I , Viral Nonstructural Proteins , COVID-19/genetics , Carrier Proteins/metabolism , Cell Line , Eukaryotic Initiation Factor-4E/metabolism , Humans , Immunity, Innate , Interferon Type I/metabolism , Protein Biosynthesis , RNA, Messenger/genetics , SARS-CoV-2 , Viral Nonstructural Proteins/metabolism , Virus Replication
10.
Diabetes Metab Res Rev ; 38(1): e3482, 2022 01.
Article in English | MEDLINE | ID: mdl-34216101

ABSTRACT

AIMS: The study aimed to elucidate the effects of rare genetic variants on the risk of type 2 diabetes (T2D). MATERIALS AND METHODS: Weighted burden analysis of rare variants was applied to a sample of 200,000 exome-sequenced participants in the UK Biobank project, of whom over 13,000 were identified as having T2D. Variant weights were allocated based on allele frequency and predicted effect, as informed by a previous analysis of hyperlipidaemia. RESULTS: There was an exome-wide significant increased burden of rare, functional variants in three genes, GCK, HNF4A and GIGYF1. GIGYF1 has not previously been identified as a diabetes risk gene and its product appears to be involved in the modification of insulin signalling. A number of other genes did not attain exome-wide significance but were highly ranked and potentially of interest, including ALAD, PPARG, GYG1 and GHRL. Loss of function (LOF) variants were associated with T2D in GCK and GIGYF1 whereas nonsynonymous variants annotated as probably damaging were associated in GCK and HNF4A. Overall, fewer than 1% of T2D cases carried one of these variants. In HNF1A and HNF1B there was an excess of LOF variants among cases but the small numbers of these fell short of statistical significance. CONCLUSIONS: Rare genetic variants make an identifiable contribution to T2D in a small number of cases but these may provide valuable insights into disease mechanisms. As larger samples become available it is likely that additional genetic factors will be identified.


Subject(s)
Diabetes Mellitus, Type 2 , Exome , Carrier Proteins/genetics , Diabetes Mellitus, Type 2/genetics , Exome/genetics , Genetic Predisposition to Disease , Humans , Polymorphism, Single Nucleotide , Risk Factors , Exome Sequencing
11.
Int J Mol Sci ; 22(17)2021 Sep 04.
Article in English | MEDLINE | ID: mdl-34502507

ABSTRACT

p38 and c-Jun N-terninal kinase (JNK) are activated in response to acute stress and inflammatory signals. Through modification of a plethora of substrates, these kinases profoundly re-shape cellular physiology for the optimal response to a harmful environment and/or an inflammatory state. Here, we utilized phospho-proteomics to identify several hundred substrates for both kinases. Our results indicate that the scale of signaling from p38 and JNK are of a similar magnitude. Among the many new targets, we highlight the regulation of the transcriptional regulators grb10-interacting GYF protein 1 and 2 (GIGYF1/2) by p38-dependent MAP kinase-activated protein kinase 2 (MK2) phosphorylation and 14-3-3 binding. We also show that the Golgi apparatus contains numerous substrates, and is a major target for regulation by p38 and JNK. When activated, these kinases mediate structural rearrangement of the Golgi apparatus, which positively affects protein flux through the secretory system. Our work expands on our knowledge about p38 and JNK signaling with important biological ramifications.


Subject(s)
MAP Kinase Kinase 4/metabolism , Stress, Physiological/physiology , p38 Mitogen-Activated Protein Kinases/metabolism , Carrier Proteins/metabolism , Cell Line, Tumor , Golgi Apparatus/metabolism , Humans , JNK Mitogen-Activated Protein Kinases/metabolism , MAP Kinase Kinase 4/physiology , MAP Kinase Signaling System/physiology , Mitogen-Activated Protein Kinase Kinases/metabolism , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation , Proto-Oncogene Proteins c-jun/metabolism , Signal Transduction , p38 Mitogen-Activated Protein Kinases/physiology
12.
Neurobiol Aging ; 100: 119.e7-119.e13, 2021 04.
Article in English | MEDLINE | ID: mdl-33239198

ABSTRACT

Rare mutations in genes originally discovered in multigenerational families have been associated with increased risk of Parkinson's disease (PD). The involvement of rare variants in DNAJC13, UCHL1, HTRA2, GIGYF2, and EIF4G1 loci has been poorly studied or has produced conflicting results across cohorts. However, they are still being often referred to as "PD genes" and used in different models. To further elucidate the role of these 5 genes in PD, we fully sequenced them using molecular inversion probes in 2408 patients with PD and 3444 controls from 3 different cohorts. A total of 788 rare variants were identified across the 5 genes and 3 cohorts. Burden analyses and optimized sequence Kernel association tests revealed no significant association between any of the genes and PD after correction for multiple comparisons. Our results do not support an association of the 5 tested genes with PD. Combined with previous studies, it is unlikely that any of these genes plays an important role in PD. Their designation as "PARK" genes should be reconsidered.


Subject(s)
Carrier Proteins , Eukaryotic Initiation Factor-4G , Genetic Association Studies/methods , High-Temperature Requirement A Serine Peptidase 2 , Molecular Chaperones , Negative Results , Parkinson Disease/genetics , Ubiquitin Thiolesterase , Cohort Studies , Female , Humans , Male , White People/genetics
13.
BMC Genet ; 21(Suppl 2): 125, 2020 12 18.
Article in English | MEDLINE | ID: mdl-33339494

ABSTRACT

BACKGROUND: The Oriental fruit fly, Bactrocera dorsalis, is a highly polyphagous invasive species with a high reproductive potential. In many tropical and subtropical parts of the world it ranks as one of the major pests of fruits and vegetables. Due to its economic importance, genetic, cytogenetic, genomic and biotechnological approaches have been applied to understand its biology and to implement the Sterile Insect Technique, currently a part of area-wide control programmes against this fly. Its chromosome complement includes five pairs of autosomes and the sex chromosomes. The X and Y sex chromosomes are heteromorphic and the highly heterochromatic and degenerate Y harbours the male factor BdMoY. The characterization of the Y chromosome in this fly apart from elucidating its role as primary sex determination system, it is also of crucial importance to understand its role in male biology. The repetitive nature of the Y chromosome makes it challenging to sequence and characterise. RESULTS: Using Representational Difference Analysis, fluorescent in situ hybridisation on mitotic chromosomes and in silico genome resources, we show that the B. dorsalis Y chromosome harbours transcribed sequences of gyf, (typo-gyf) a homologue of the Drosophila melanogaster Gigyf gene, and of a non-LTR retrotransposon R1. Similar sequences are also transcribed on the X chromosome. Paralogues of the Gigyf gene are also present on the Y and X chromosomes of the related species B. tryoni. Another identified Y-specific repetitive sequence linked to BdMoY appears to be specific to B. dorsalis. CONCLUSIONS: Our random scan of the Y chromosome provides a broad picture of its general composition and represents a starting point for further applicative and evolutionary studies. The identified repetitive sequences can provide a useful Y-marking system for molecular karyotyping of single embryos. Having a robust diagnostic marker associated with BdMoY will facilitate studies on how BdMoY regulates the male sex determination cascade during the embryonic sex-determination window. The Y chromosome, despite its high degeneracy and heterochromatic nature, harbours transcribed sequences of typo-gyf that may maintain their important function in post-transcriptional mRNA regulation. That transcribed paralogous copies of Gigyf are present also on the X and that this genomic distribution is maintained also in B. tryoni raises questions on the evolution of sex chromosomes in Bactrocera and other tephritids.


Subject(s)
Genetic Markers , Tephritidae/genetics , Y Chromosome/genetics , Animals , Female , Genes, Insect , In Situ Hybridization, Fluorescence , Karyotyping , Male , Repetitive Sequences, Nucleic Acid , Retroelements , Sex Characteristics
14.
Mol Autism ; 11(1): 92, 2020 11 23.
Article in English | MEDLINE | ID: mdl-33225984

ABSTRACT

BACKGROUND: The regulation of protein synthesis is a critical step in gene expression, and its dysfunction is implicated in autism spectrum disorder (ASD). The eIF4E homologous protein (4EHP, also termed eIF4E2) binds to the mRNA 5' cap to repress translation. The stability of 4EHP is maintained through physical interaction with GRB10 interacting GYF protein 2 (GIGYF2). Gene-disruptive mutations in GIGYF2 are linked to ASD, but causality is lacking. We hypothesized that GIGYF2 mutations cause ASD by disrupting 4EHP function. METHODS: Since homozygous deletion of either gene is lethal, we generated a cell-type-specific knockout model where Eif4e2 (the gene encoding 4EHP) is deleted in excitatory neurons of the forebrain (4EHP-eKO). In this model, we investigated ASD-associated synaptic plasticity dysfunction, ASD-like behaviors, and global translational control. We also utilized mice lacking one copy of Gigyf2, Eif4e2 or co-deletion of one copy of each gene to further investigate ASD-like behaviors. RESULTS: 4EHP is expressed in excitatory neurons and synaptosomes, and its amount increases during development. 4EHP-eKO mice display exaggerated mGluR-LTD, a phenotype frequently observed in mouse models of ASD. Consistent with synaptic plasticity dysfunction, the mice displayed social behavior impairments without being confounded by deficits in olfaction, anxiety, locomotion, or motor ability. Repetitive behaviors and vocal communication were not affected by loss of 4EHP in excitatory neurons. Heterozygous deletion of either Gigyf2, Eif4e2, or both genes in mice did not result in ASD-like behaviors (i.e. decreases in social behavior or increases in marble burying). Interestingly, exaggerated mGluR-LTD and impaired social behaviors were not attributed to changes in hippocampal global protein synthesis, which suggests that 4EHP and GIGYF2 regulate the translation of specific mRNAs to mediate these effects. LIMITATIONS: This study did not identify which genes are translationally regulated by 4EHP and GIGYF2. Identification of mistranslated genes in 4EHP-eKO mice might provide a mechanistic explanation for the observed impairment in social behavior and exaggerated LTD. Future experiments employing affinity purification of translating ribosomes and mRNA sequencing in 4EHP-eKO mice will address this relevant issue. CONCLUSIONS: Together these results demonstrate an important role of 4EHP in regulating hippocampal plasticity and ASD-associated social behaviors, consistent with the link between mutations in GIGYF2 and ASD.


Subject(s)
Eukaryotic Initiation Factor-4E/metabolism , Hippocampus/physiopathology , Long-Term Synaptic Depression/physiology , Social Behavior , Animals , Anxiety/physiopathology , Autism Spectrum Disorder/genetics , Behavior, Animal , Carrier Proteins/genetics , Heterozygote , Hippocampus/pathology , Male , Mice, Inbred C57BL , Mice, Knockout , Models, Biological , Motor Activity , Mutation/genetics , Neurons/metabolism , RNA Caps/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Metabotropic Glutamate/metabolism , Smell , Social Interaction , Synaptosomes/metabolism
15.
DNA Cell Biol ; 37(12): 1044-1054, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30376373

ABSTRACT

Grb10 (growth factor receptor-bound protein 10)-interacting GYF protein 1 (GIGYF1) can modulate insulin-like growth factor 1 receptor (IGF1R) signaling pathway, which plays an important role in regulating diabetes-associated cognitive impairment, by linking to Grb10 adapter. However, it remains unclear whether endogenous GIGYF1 expression is associated with the development of diabetes-related cognitive impairment. In this study, we measured the expression level of GIGYF1, Grb10, phosphorylated IGF1R/IGF1R, phosphorylated AKT serine/threonine protein kinase/protein kinase B (AKT)/AKT, and phosphorylated extracellular signal-regulated kinase (ERK)/ERK in human neuroblastoma SHSY-5Y cells. Meanwhile, we detected cell apoptosis, proliferation, and migration. Our results showed that the percentage of apoptotic cells increased along with the increasing concentrations of glucose (0-200 mM). The expression of GIGYF1 had a significant increase in the presence of 25 mM concentration of glucose in SHSY-5Y cells. In addition, high glucose augmented the expression of IGF1R and Grb10, but decreased the expression of p-IGF1R, p-AKT, and p-ERK. However, GIGYF1 knockdown reversed the decline in the expression of p-IGF1R, p-AKT, and p-ERK. In addition, knocking down GIGYF1 promoted the proliferation and migration of SHSY-5Y cells, but inhibited the apoptosis in SHSY-5Y cells. These results demonstrate that the expression of GIGYF1 can regulate IGF1R signaling pathway in high glucose-induced SHSY-5Y cells.


Subject(s)
Carrier Proteins/genetics , Glucose/pharmacology , Receptor, IGF Type 1/metabolism , Signal Transduction , Apoptosis , Carrier Proteins/metabolism , Cell Line, Tumor , Cell Movement , Humans , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Neurons/drug effects , Neurons/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Receptor, IGF Type 1/genetics
16.
Curr Protein Pept Sci ; 18(7): 765-778, 2017.
Article in English | MEDLINE | ID: mdl-26965686

ABSTRACT

In order to explain the molecular causes of Parkinson's Disease (PD) it is important to understand the effect that mutations described as causative of the disease have at the functional level. In this special issue, several authors have been reviewing the effects in PD and other parkinsonisms of mutations described in LRRK2, α-synuclein, PINK1-Parkin-DJ-1, UCHL1, ATP13A2, GBA, VPS35, FBOX7 and HTRA2. In this review, we compile the knowledge about other proteins with a more general role in neurodegenerative diseases (MAPT) or for which less data is available due to its recent discovery (EIF4G1, DNAJC13), the lack of structural or functional data (as for PLA2G6 or DNAJC6), or even their doubtful association with the disease (as for GIGYF2, SYNJ1 and SPR). Also the cellular pathways involved in this disease are reviewed, with the goal of having an overview of the effects on the proteins and its possible role in the disease. This knowledge could also serve as the basis for designing tools that may potentially be used as a treatment for the disease, such as inhibitory or activating molecules, as well as other involved in regulating the half-life of the proteins involved.


Subject(s)
Mitochondria/metabolism , Mutation , Parkinson Disease/genetics , Alcohol Oxidoreductases/genetics , Alcohol Oxidoreductases/metabolism , Biological Transport/genetics , Carrier Proteins/genetics , Carrier Proteins/metabolism , Eukaryotic Initiation Factor-4G/genetics , Eukaryotic Initiation Factor-4G/metabolism , Gene Expression , Group VI Phospholipases A2/genetics , Group VI Phospholipases A2/metabolism , HSP40 Heat-Shock Proteins/genetics , HSP40 Heat-Shock Proteins/metabolism , Humans , Mitochondria/pathology , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Parkinson Disease/metabolism , Parkinson Disease/pathology , Phosphoric Monoester Hydrolases/genetics , Phosphoric Monoester Hydrolases/metabolism , Synaptic Transmission/genetics , tau Proteins/genetics , tau Proteins/metabolism
17.
Biochem Biophys Res Commun ; 475(3): 289-94, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27157137

ABSTRACT

In mammalian post-transcriptional gene silencing, the Argonaute protein AGO2 indirectly recruits translation inhibitors, deadenylase complexes, and decapping factors to microRNA-targeted mRNAs, thereby repressing mRNA translation and accelerating mRNA decay. However, the exact composition and assembly pathway of the microRNA-induced silencing complex are not completely elucidated. As the GYF domain of human GIGYF2 was shown to bind AGO2 in pulldown experiments, we wondered whether GIGYF2 could be a novel protein component of the microRNA-induced silencing complex. Here we show that full-length GIGYF2 coimmunoprecipitates with AGO2 in human cells, and demonstrate that, upon tethering to a reporter mRNA, GIGYF2 exhibits strong, dose-dependent silencing activity, involving both mRNA destabilization and translational repression.


Subject(s)
Argonaute Proteins/metabolism , Carrier Proteins/metabolism , Gene Silencing , Protein Biosynthesis , RNA, Messenger/genetics , Genes, Reporter , HEK293 Cells , HeLa Cells , Humans , Protein Interaction Maps , RNA Stability , RNA, Messenger/chemistry , RNA, Messenger/metabolism
18.
Neurol Sci ; 36(11): 2073-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26152800

ABSTRACT

The contribution of the gene of GIGYF2, Grb10-Interacting GYF Protein 2, to Parkinson's disease (PD) is still ambiguous. To explore the contribution of GIGYF2 to PD at the genetic level, we analyzed the relationship between all reported GIGYF2 variants (including mutations and polymorphisms) and PD through a meta-analysis. Databases including Medline, Embase, etc., were searched to find relevant studies. All eligible publications have to meet the strict inclusion and exclusion criteria listed. Two authors independently selected trials, assessed the article's quality and extracted data. Odds ratios (ORs) and relative risks with 95 % confidence intervals (CIs) were used to evaluate the strength of associations. All analyses were carried out by using the Review Manager software package v.5.2. More than 100 variants of GIGYF2 were reported either or both in patients and controls in 10 included publications. The 10 publications totally included 5466 patients and 6517 controls. We conducted meta-analyses for the following variants: N56S, N457T, Del LPQQQQQQ 1209-1216, Del Q 1210 (rs10555297), rs12328151, rs2289912, rs2305138, rs3816334, A572A and H1171R. The ORs for N56S were 2.86 (95 % CI 1.10, 7.41) for PD and 4.75 (95 % CI 1.35, 16.68) for FPD. And the OR for N457T in FPD was 4.53 (95 % CI 1.04, 19.66). On the other hand, other variants involved in meta-analyses were not related to PD. This research results suggest that the N56S and N457T of GIGYF2 are risk factors for PD in Caucasians, but not in Asians.


Subject(s)
Carrier Proteins/genetics , Genetic Predisposition to Disease , Mutation , Parkinson Disease/genetics , Polymorphism, Genetic , Asian People/genetics , Humans , Parkinson Disease/ethnology , Risk Factors , White People/genetics
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