| 2003 |
GIMAP5 (Irod/Ian5) protects Jurkat T-cells against okadaic acid- and gamma-radiation-induced apoptosis by antagonizing a calmodulin-dependent protein kinase II (CaMKII)-dependent step upstream of caspase-3 activation. The protein localizes to the centrosomal/Golgi/endoplasmic reticulum compartment, and deletion of either the C-terminal membrane-binding domain or the N-terminal GTP-binding domain did not abolish antiapoptotic function; the central coiled-coil domain was responsible for centrosomal anchoring and apoptosis resistance. |
Overexpression in Jurkat cells, deletion mutagenesis, caspase-3 activity assay, CaMKII inhibitor experiments, confocal microscopy |
Molecular biology of the cell |
Medium |
12925764
|
| 2004 |
A transgenic rescue experiment demonstrated that wild-type Ian5 (GIMAP5) protein is directly and specifically required for maintaining normal peripheral T cell numbers: a 150-kb PAC transgene harboring wild-type Ian5 completely restored T cell lymphopenia in F344.lyp/lyp rats carrying the frameshift mutation. |
Transgenic rescue (PAC transgene) in F344.lyp/lyp rats with quantitative T cell reconstitution |
Physiological genomics |
High |
15328390
|
| 2007 |
GIMAP5 localizes to a sedimentable subcellular fraction distinct from mitochondria and ER in primary rat T lymphocytes. Despite this distinct localization, T cells from GIMAP5-deficient rats display rapid loss of mitochondrial membrane potential, indicating GIMAP5 regulates T lymphocyte survival through mechanisms operating upstream of mitochondria. |
Subcellular fractionation, confocal microscopy with epitope-tagged GIMAP5 (intact C-terminal membrane anchor), mitochondrial membrane potential assay in primary T cells |
Biochemical and biophysical research communications |
Medium |
17655828
|
| 2007 |
Overexpression of GIMAP5 in Jurkat cells and naive human T cells induced apoptosis, while siRNA-mediated knockdown did not affect apoptosis. Both wild-type rat Gimap5 and the BBDP frameshift mutant (Gimap5-lyp) induced apoptosis upon overexpression in rat T cells, with Gimap5-lyp causing greater cell death. GIMAP5 was localized to the endoplasmic reticulum, and endogenous GIMAP5 mRNA was upregulated in activated T cells. |
siRNA knockdown, transient overexpression, flow cytometry (apoptosis), qPCR, subcellular localization (confocal microscopy) |
International immunology |
Medium |
17369194
|
| 2008 |
Selective gene ablation of mouse Gimap5 impairs final intrathymic maturation of CD8 and CD4 T cells and compromises survival of postthymic CD4 and CD8 cells. Gimap5 deficiency also blocks NK and NKT cell differentiation; NK/NKT development is restored by transfer of Gimap5−/− bone marrow into a wild-type environment, demonstrating a cell-extrinsic component for NK/NKT rescue. |
Conditional gene knockout in mice, bone marrow transfer, flow cytometric analysis of lymphocyte subsets |
Blood |
High |
18796632
|
| 2008 |
Loss of GIMAP5 impairs calcium flux in T lymphocytes: Gimap5-deficient T cells show diminished Ca2+ influx following thapsigargin treatment or TCR stimulation, while thapsigargin-induced Ca2+ release from intracellular stores is unaffected. The defect is manifested in mature single-positive thymocytes, where the survival defect first occurs. |
Intracellular Ca2+ flux assays (thapsigargin, TCR stimulation) in BBDP rat T cells and thymocytes |
Molecular immunology |
Medium |
19007993
|
| 2009 |
In Gimap5-deficient (BBDP) rat T cells, ER stress markers (chaperones) are elevated and apoptotic signaling proceeds through CHOP (C/EBP-homologous protein). siRNA-mediated knockdown of CHOP protected Gimap5-deficient T cells from ER stress-induced apoptosis, establishing CHOP as a downstream effector of GIMAP5 deficiency in T cell death. |
Western blot for ER stress chaperones, siRNA knockdown of CHOP, apoptosis assays in primary T cells from Gimap5−/− rats |
PloS one |
Medium |
19424493
|
| 2010 |
Gimap5 is required for lymphocyte quiescence and antigen-receptor-induced proliferation. A P-loop missense mutation in Gimap5 (ENU-induced) causes CD4+ T cell and B cell failure to proliferate upon antigen-receptor stimulation despite normal NF-κB, MAP kinase, and Akt activation. Fetal liver chimera experiments demonstrated this is hematopoietic cell-intrinsic. Antibiotic treatment and adoptive transfer of Rag-sufficient splenocytes ameliorated intestinal inflammation. |
ENU mutagenesis, fetal liver chimera transplantation, lymphocyte proliferation assays, signaling pathway analysis (NF-κB, MAPK, Akt), antibiotic treatment, adoptive transfer |
Journal of immunology |
High |
20190135
|
| 2010 |
Endogenous GIMAP5 localizes to lysosomes and multivesicular bodies in lymphoid cells (rat, mouse, and human systems), as established by confocal microscopy with lysosomal markers, subcellular fractionation with immunoblotting, and electron microscopy of inducible epitope-tagged GIMAP5 in Jurkat cells. GIMAP1, in contrast, localizes to the Golgi. |
Confocal microscopy with lysosomal markers, subcellular fractionation + immunoblotting using novel monoclonal antibodies, electron microscopy in inducible Jurkat cells |
Self/nonself |
High |
21487483
|
| 2011 |
Gimap5 binds Bcl-2 family members. Gimap5 deficiency disrupts the interaction between Mcl-1 and HSC70, enhancing Mcl-1 degradation and compromising mitochondrial integrity in hematopoietic progenitor cells. Gimap5-deficient HSCs show more apoptosis and defective long-term repopulation capacity. |
Co-immunoprecipitation (Gimap5-Bcl-2 and Mcl-1/HSC70 interaction), apoptosis assays, bone marrow transplantation/repopulation assays |
The Journal of experimental medicine |
Medium |
21502331
|
| 2011 |
In Gimap5-deficient mice, CD4+ T cells become Th1/Th17 polarized and drive colitis. Loss of Gimap5 is associated with progressive loss of Foxo1, Foxo3, and Foxo4 protein expression in CD4+ T cells, and regulatory T cells are reduced in frequency with impaired immunosuppressive capacity. |
ENU mutant mouse model, intracellular cytokine staining, Foxo protein expression (Western blot), Treg functional assays |
Journal of immunology |
Medium |
22106000
|
| 2013 |
GIMAP5 promotes mitochondrial Ca2+ accumulation following capacitative entry. Overexpression of GIMAP5 in HEK-293 cells increases mitochondrial Ca2+ sequestration; microtubule disruption (but not actin disruption) abrogated mitochondrial Ca2+ buffering in primary T cells. GIMAP5 partially co-localizes with tubulin in HEK-293 cells. |
Ca2+ imaging in primary rat T cells and HEK-293 overexpression, microtubule/actin disruption pharmacology, confocal co-localization |
The Biochemical journal |
Medium |
23098229
|
| 2013 |
Gimap3 and Gimap5 cooperate to maintain T cell numbers. Double knockout of Gimap3 and Gimap5 causes more severe T cell lymphopenia than Gimap5 single knockout. Retroviral overexpression of Gimap3 elevated T cell production in irradiated mice; shRNA knockdown reduced it. Both Gimap3 and Gimap5 associate with antiapoptotic Bcl-2 family proteins. |
Double KO mouse generation, competitive hematopoietic transplantation, retroviral overexpression, shRNA knockdown, flow cytometric T cell counting, Co-IP |
European journal of immunology |
High |
24510501
|
| 2015 |
Loss of Gimap5 results in increased basal activation of mTOR (mammalian target of rapamycin) and constitutive activation of the PI3K pathway in T lymphocytes, independent of PP2A or AMPK. |
Phospho-protein immunoblotting (mTOR, Akt, PI3K pathway), pharmacological inhibitors (rapamycin, PP2A inhibitor, AMPK inhibitor) in Gimap5-deficient mouse T cells |
PloS one |
Medium |
26440416
|
| 2015 |
Quantitative changes in Gimap5 expression affect mitochondrial DNA (mtDNA) segregation in mouse hematopoietic tissues, consistent with its lysosomal localization. Gimap5 encodes a lysosomal protein, whereas its paralog Gimap3 localizes to the endoplasmic reticulum (not mitochondria as previously reported). |
Heteroplasmic mouse model, allele-specific expression analysis, uORF translational regulation analysis, subcellular localization studies |
Genetics |
Medium |
25808953
|
| 2016 |
Functional Gimap5 is required for optimal TCR signaling and IL-7 receptor signaling in T cells: T cells from Gimap5-deficient OTII TCR-transgenic mice fail to proliferate to cognate antigen, and Gimap5-deficient T cells (rat and mouse) show decreased STAT5 phosphorylation following IL-7 stimulation. |
Antigen-specific proliferation assay (OTII), STAT5 phosphorylation by Western blot/flow cytometry following IL-7 stimulation, loss-of-function mouse and rat models |
PloS one |
Medium |
27023180
|
| 2018 |
Gimap5 is essential for inactivation of glycogen synthase kinase-3β (GSK3β) following T cell activation. In the absence of Gimap5, constitutively active GSK3β constrains c-Myc induction and NFATc1 nuclear import, limiting CD4+ T cell proliferation. Gimap5 also facilitates Ser389 phosphorylation and nuclear translocation of GSK3β to limit DNA damage. Pharmacological or genetic inhibition of GSK3β rescues Gimap5-deficient CD4+ T cells and ameliorates immunopathology in mice. A human patient with GIMAP5 loss-of-function shows lymphopenia and impaired T cell proliferation rescued by GSK3 inhibitors. |
KO mice, phospho-GSK3β/c-Myc/NFATc1 immunoblot and nuclear import assays, pharmacological GSK3β inhibition, conditional genetic GSK3β targeting, in vitro proliferation assays with human patient cells, rescue experiments |
Nature communications |
High |
29382851
|
| 2018 |
Gimap5 deficiency causes increased DNA damage in CD4+ T cells particularly under TH1-polarizing conditions. TGF-β can control DNA damage in Gimap5-deficient cells, thereby promoting TH17 polarization as a selective survival mechanism. |
T cell polarization assays, DNA damage quantification (γH2AX), TGF-β treatment, conditional Gimap5fl/flCd4Cre/ert2 mice, human GIMAP5 LOF patient cells |
The Journal of allergy and clinical immunology |
Medium |
30616774
|
| 2021 |
GIMAP5 is expressed in hepatic endothelial cells; its loss (in humans via homozygous damaging mutations and in mice via knockout) results in capillarization of liver sinusoidal endothelial cells (LSECs). Endothelial cell-selective deletion of GIMAP5 reproduces this phenotype. Single-cell RNA-seq places GIMAP5 upstream of GATA4, a transcription factor required for LSEC specification. |
Human genetic analysis (homozygous mutation identification), mouse KO, endothelial cell-selective conditional KO, single-cell RNA-sequencing, histology/immunofluorescence for LSEC markers |
The Journal of experimental medicine |
High |
33956074
|
| 2021 |
Gimap5 interacts with M6PR (mannose-6-phosphate receptor) and promotes M6PR translocation from cytoplasm to the cell membrane, thereby inhibiting PADI4-mediated EMT in lung cancer cell lines. |
Co-IP combined with mass spectrometry, overexpression in lung cancer cell lines, immunofluorescence for M6PR distribution, migration/invasion/proliferation assays |
Frontiers in oncology |
Low |
34604035
|
| 2023 |
MFSD1 and GLMP associate with GIMAP5 in a protein complex. MFSD1 and GLMP interactions with GIMAP5 are essential to maintain normal GIMAP5 expression levels, which in turn support lymphocyte development and liver homeostasis. |
Proteomic analysis (MS) of MFSD1 interactome, ENU alleles + germline KO of Mfsd1/Glmp/Gimap5, immunoblotting for GIMAP5 protein levels, flow cytometry for lymphocyte populations |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
38055739
|
| 2023 |
Gimap5 promotes RSV degradation in lysosomes by interacting with M6PR and prevents RSV invasion by downregulating expression of the RSV surface receptor IGF1R. |
Co-IP, Western blot, immunofluorescence, transmission electron microscopy of RSV degradation in Gimap5-overexpressed or -silenced cell lines |
Journal of medical virology |
Low |
36484389
|
| 2024 |
GIMAP5 restricts pathological accumulation of long-chain ceramides (CERs) by interacting with protein kinase CK2 and attenuating CK2's ability to activate ceramide synthases. Inhibition of CK2 or ceramide synthase rescues GIMAP5-deficient T cells from CER overaccumulation and cell deterioration. |
Co-IP (GIMAP5-CK2 interaction), lipidomic profiling, CK2 and ceramide synthase pharmacological inhibition, functional rescue of GIMAP5-deficient T cells, human genetic disease characterization |
Nature immunology |
High |
38172257
|