Human inositol polyphosphate multikinase regulates transcript-selective nuclear mRNA export to preserve genome integrity
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE49658 | GEO | 2013/09/27
SECONDARY ACCESSION(S): PRJNA214656
REPOSITORIES: GEO
Similar Datasets
Project description:Messenger (m)RNA export from the nucleus is essential for eukaryotic gene expression. Here, we identify a transcript-selective nuclear export mechanism affecting certain human transcripts, enriched for functions in genome duplication and repair, controlled by inositol polyphosphate multikinase (IPMK), an enzyme catalyzing inositol polyphosphate and phosphoinositide turnover. We studied transcripts encoding RAD51, a protein essential for DNA repair by homologous recombination (HR), to characterize the mechanism underlying IPMK-regulated mRNA export. IPMK depletion or catalytic inactivation selectively decreases the nuclear export of RAD51 mRNA, and RAD51 protein abundance, thereby impairing HR. Recognition of a sequence motif in the untranslated region of RAD51 transcripts by the mRNA export factor ALY requires IPMK. Phosphatidylinositol (3,4,5)-trisphosphate (PIP3), an IPMK product, restores ALY recognition in IPMK-depleted cell extracts, suggesting a mechanism underlying transcript selection. Our findings implicate IPMK in a transcript-selective mRNA export pathway controlled by phosphoinositide turnover that preserves genome integrity in humans. We used gene expression profiling to compare the abundance of cytoplasmic RNAs after IPMK depletion
2013-09-27 | E-GEOD-49658 | biostudies-arrayexpress
Project description:Inositol polyphosphate multikinase (IPMK), a key enzyme in the inositol polyphosphate (IP) metabolism, is a pleiotropic signaling factor involved in major biological events, including transcriptional control. In the yeast, IPMK and its IP products promote the activity of the chromatin-remodeling complex SWI/SNF, which plays a critical role in gene expression by regulating chromatin accessibility. However, the direct link between IPMK and chromatin remodelers remains unclear, raising a question on how IPMK contributes to the transcriptional regulation in mammals. By employing unbiased screening approaches and in vivo/in vitro immunoprecipitations, here we demonstrated that mammalian IPMK physically interacts with the SWI/SNF complex by directly binding to SMARCB1, BRG1, and SMARCC1. Furthermore, we identified the specific domains required for the IPMK-SMARCB1 binding. Notably, using the CUT&RUN and ATAC-seq assays, we discovered that IPMK co-localizes with BRG1 and regulates BRG1 localization as well as BRG1-mediated chromatin accessibility in a genome-wide manner in mouse embryonic stem cells. Finally, our mRNA-seq analyses revealed that IPMK and SMARCB1 regulate the expression of a common gene set, validating a functional link between IPMK and the SWI/SNF complex. Together, these findings show that IPMK regulates promoter-targeting of the SWI/SNF complex and thereby contributes to SWI/SNF-meditated chromatin accessibility, transcription, and differentiation.
2022-05-10 | GSE158525 | GEO
Project description:Activated Foxp3+ regulatory T (Treg) cells differentiate into effector Treg (eTreg) cells to maintain peripheral immune homeostasis and tolerance. T cell receptor (TCR)-mediated induction and regulation of store-operated Ca2+ entry (SOCE) is essential for eTreg cell differentiation and function. However, SOCE regulation in Treg cells remains unclear. Here we show that inositol polyphosphate multikinase (IPMK), which generates inositol tetrakisphosphate and inositol pentakisphosphate, is a pivotal regulator of Treg cell differentiation downstream of TCR signaling. IPMK is highly expressed in TCR-stimulated Treg cells and promotes a TCR-induced Treg cell program. IPMK-deficient Treg cells display aberrant T cell activation and impaired differentiation into RORγt+ Treg cells, and tissue-resident Treg cells. Mechanistically, IPMK controls the generation of higher-order inositol phosphates, thereby promoting Ca2+ mobilization and Treg cell effector functions. Our findings identify IPMK as a critical regulator of TCR-mediated Ca2+ influx and highlight the importance of IPMK in Treg cell-mediated immune homeostasis.
2023-05-18 | GSE198960 | GEO
Project description:Human inositol polyphosphate multikinase regulates transcript-selective nuclear mRNA export to preserve genome integrity
| PRJNA214656 | ENA
Project description:Intestinal homeostasis is dynamically coordinated by various types of epithelial cells fulfilling their specific functions. Tuft cells as chemosensory cells have emerged as key players of the host response, such as innate immunity. Tuft cells are also critical for the restoration of intestinal architecture upon damage, thereby contributing to inflammatory bowel diseases (IBDs) characterized by defective intestinal barrier integrity. However, the molecular mechanism of how tuft cell homeostasis is controlled remains obscure. Recent studies have identified single-nucleotide polymorphisms in the inositol polyphosphate multikinase (IPMK) gene associated with IBD predisposition. IPMK, an essential enzyme for inositol phosphate metabolism, has been known to mediate major biological events such as growth. To investigate the functional significance of IPMK in gut epithelium, we generated intestinal epithelial cell (IEC)-specific Ipmk knockout (IPMKΔIEC) mice. Whereas IPMKΔIEC mice developed normally and showed no intestinal abnormalities during homeostasis, Ipmk deletion aggravated dextran sulfate sodium (DSS)-induced colitis, with higher clinical colitis scores, and elevated epithelial barrier permeability. Surprisingly, no apparent defects in epithelial growth signaling pathway and inflammation were found in DSS-challenged, IPMK-deficient colons. Rather, Ipmk deletion led to a significant decrease in the number of tuft cells without influencing other intestinal epithelial cells. Ipmk deletion in the gut epithelium was found to reduce choline acetyltransferase but not cytokines (e.g., IL-25), suggesting selective loss of cholinergic signaling. Single-cell RNA-sequencing of mouse colonic tuft cells (EpCAM+/Siglec F+) and immunohistochemistry revealed three populations of tuft cells and further showed that, in IPMKΔIEC mice, a transcriptionally inactive tuft club cell population was markedly expanded, and neuronal-related tuft cells were relatively decreased, supporting the abnormal development of tuft cells without IPMK functions. Thus, IPMK acts as a physiological determinant of colonic tuft cell homeostasis, thereby mediating tissue regeneration upon injury.
2022-10-26 | GSE200284 | GEO
Project description:Transgenic Arabidopsis plants with constitutively low inositol (1,4,5) triphosphate exhibit an increased tolerance to water stress by an ABA-independent pathway; The phosphoinositide pathway and inositol (1,4,5) trisphopsphate (InsP3) are implicated in plant responses to stress. In order to manipulate the pathway and determine the downstream consequences of altered InsP3-mediated signaling, we generated transgenic Arabidopsis plants expressing the mammalian type I inositol polyphosphate 5-phosphatase, an enzyme that specifically hydrolyzes the soluble inositol phosphates and terminates the signal. Transgenic plants have no morphological differences compared to wild type; however, rapid transient Ca2+ responses to a cold or salt stimulus are reduced by ~ 30%. To further understand the role of InsP3-mediated signaling in plant stress responses we focused on drought stress. Surprisingly, the InsP 5-ptase plants lose less water and exhibited an increased tolerance to drought. Stomatal bioassays showed that transgenic guard cells are less responsive to the inhibition of opening by ABA but show an increased sensitivity to ABA-induced closure. The onset of the drought stress is delayed in the transgenic plants and ABA levels did not increase as much as in the wild type. Transcript profiling has revealed that DREB2A and a subset of DREB2A regulated genes are basally up regulated in the InsP 5-ptase plants. These results indicate that the drought tolerance of the InsP 5-ptase plants is mediated in part via an ABA-independent pathway. The constitutive dampening of the InsP3 signal in this system has uncovered novel regulation and cross talk between signaling pathways. Experiment Overall Design: In order to compare global expression profiles between wild type and transgenic plants in response to water stress we harvested leaves for transcript profiling at day 0 (well watered) and at day 7 when the transgenic plants were still at an RWC of >85% and the wild type and vector control plants were at an RWC of ~ 50 -60% . Leaves were harvested and pooled from ~ 10 plants of each line/time point and three independent biological replicates were carried out with wild type (WT) and 2 independent transgenic lines (T6 and T8). The vector control line (C2) was used as an additional control.
2008-10-25 | E-GEOD-10670 | biostudies-arrayexpress
Project description:Transgenic Arabidopsis plants with constitutively low inositol (1,4,5) triphosphate exhibit an increased tolerance to water stress by an ABA-independent pathway The phosphoinositide pathway and inositol (1,4,5) trisphopsphate (InsP3) are implicated in plant responses to stress. In order to manipulate the pathway and determine the downstream consequences of altered InsP3-mediated signaling, we generated transgenic Arabidopsis plants expressing the mammalian type I inositol polyphosphate 5-phosphatase, an enzyme that specifically hydrolyzes the soluble inositol phosphates and terminates the signal. Transgenic plants have no morphological differences compared to wild type; however, rapid transient Ca2+ responses to a cold or salt stimulus are reduced by ~ 30%. To further understand the role of InsP3-mediated signaling in plant stress responses we focused on drought stress. Surprisingly, the InsP 5-ptase plants lose less water and exhibited an increased tolerance to drought. Stomatal bioassays showed that transgenic guard cells are less responsive to the inhibition of opening by ABA but show an increased sensitivity to ABA-induced closure. The onset of the drought stress is delayed in the transgenic plants and ABA levels did not increase as much as in the wild type. Transcript profiling has revealed that DREB2A and a subset of DREB2A regulated genes are basally up regulated in the InsP 5-ptase plants. These results indicate that the drought tolerance of the InsP 5-ptase plants is mediated in part via an ABA-independent pathway. The constitutive dampening of the InsP3 signal in this system has uncovered novel regulation and cross talk between signaling pathways. Keywords: drought stress, expression study
2008-09-01 | GSE10670 | GEO
Project description:In eukaryotes, inositol polyphosphates perform essential metabolic and signaling functions. Using human fungal pathogen Cryptococcus neoformans as a model, we created mutants in three inositol polyphosphates kinases: Arg1, Ipk1 and Kcs1. Each of the mutants produces a unique repertoire of inositol polyphosphates, different from the wild type strain. Comparative phenotypic and transcriptome analyses of wild type and mutant strains indicates that inositol polyphosphate PP-IP5 (IP7) is the key regulator of gene expression, fitness and virulence in C. neoformans.
2016-03-03 | GSE78824 | GEO
Project description:In eukaryotes, inositol polyphosphates perform essential metabolic and signaling functions. Using human fungal pathogen Cryptococcus neoformans as a model, we created mutants in three inositol polyphosphates kinases: Arg1, Ipk1 and Kcs1. Each of the mutants produces a unique repertoire of inositol polyphosphates, different from the wild type strain. Comparative phenotypic and transcriptome analyses of wild type and mutant strains indicates that inositol polyphosphate PP-IP5 (IP7) is the key regulator of gene expression, fitness and virulence in C. neoformans. Comparison of WT and mutants (Darg1, Dkcs1 and Dipk1) grown in broth culture in the absence of stress.
2016-03-03 | E-GEOD-78824 | biostudies-arrayexpress
Project description:The quality control and export of mRNA by RNA-binding proteins are necessary for the survival of malaria parasites, which have complex life cycles. Malarial nuclear poly(A) binding protein 2 (NAB2), ALWAYS EARLY (ALY) and serine/arginine-rich (SR) proteins, such as nucleolar protein 3 (NPL3), G-strand binding protein 2 (GBP2) and SR1, are involved in nuclear mRNA export in malaria parasites. However, their functions and cellular localization are not fully understood. In this study, we found that NAB2 and SR1, but not ALY, NPL3 or GBP2, played essential roles in the asexual development of malaria parasites, while GBP2 was involved in gametocyte production. Moreover, GBP2 localized to both the nucleus and cytoplasm of malaria parasites and interacted with the proteins ALBA4, DOZI and CITH, which play roles in translational repression. Our findings suggest that malarial GBP2 may be involved in the recruitment of ALBA4, DOZI and CITH. Immunoprecipitation coupled to mass spectrometry (IP-MS) revealed that PHAX domain-containing protein, an adaptor protein for exportin-1, also interacted with GBP2, suggesting that mRNA export occurs via the PHAX domain-containing protein pathway in malaria parasites. Fluorescence live cell imaging revealed that malarial NAB2 localized at the nuclear periphery and co-localized with NUP205. Moreover, using IP-MS, we found that malarial NAB2 interacted with transportin. RNA immunoprecipitation coupled to RNA sequencing revealed that malarial NAB2 bound directly to 143 mRNAs, including those encoding 40S and 60S ribosomal proteins. This indicates that malarial NAB2 is involved in general mRNA assembly and is shuttled between the nucleus and cytoplasm. Our findings suggest that unique mRNA export and post-transcriptional gene regulation mediated by RNA-binding proteins occur in malaria parasites.
2021-11-03 | PXD027302 | Pride