Affinage

ARHGAP25

Rho GTPase-activating protein 25 · UniProt P42331

Length
645 aa
Mass
73.4 kDa
Annotated
2026-06-09
20 papers in source corpus 16 papers cited in narrative 16 extracted findings
Cross-family judge vs UniProt: tie faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

ARHGAP25 is a Rac-specific GTPase-activating protein (RacGAP) expressed predominantly in hematopoietic cells that inactivates Rac to negatively regulate actin cytoskeletal dynamics and Rac-dependent cellular behaviors (PMID:22096251). Through its GAP domain it engages small GTPases including RAC2 and RHOG in a GTP/GDP activation-state-dependent manner, and its activity is gated by phosphorylation at S363 and S488 (PMID:36190314, PMID:39210013). By converting Rac to its inactive GDP-bound state, ARHGAP25 restrains phagocytosis in neutrophils and macrophages, and its loss elevates active Rac in leukocytes, augmenting cytoskeletal remodeling and transendothelial neutrophil migration cell-intrinsically (PMID:22096251, PMID:27566826). Beyond innate immune cells it controls B cell development and CXCR4/CXCL12-driven chemotaxis and shapes inflammatory arthritis severity via the I-κB/NF-κB/IL-1β axis (PMID:32434881, PMID:37234175). ARHGAP25 function is positively regulated at lamellipodia by physical interaction with septin2, which enhances its suppression of Rac-dependent lamellipodia formation and cell spreading (PMID:40205813). In multiple cancers ARHGAP25 acts as a Rac1-suppressing tumor restraint, dampening Rac1/PAK1 signaling and thereby attenuating downstream AKT/mTOR and Wnt/β-catenin pathways to limit proliferation, migration, invasion, and HIF-1α-driven glycolysis (PMID:31228451, PMID:33994864, PMID:37326327). A loss-of-function missense variant p.G218R that reduces GAP activity toward Rac1 causes early-onset autosomal-dominant skeletal fragility, directly linking ARHGAP25 dysfunction to a Mendelian bone phenotype (PMID:34258505).

Mechanistic history

Synthesis pass · year-by-year structured walk · 12 steps
  1. 2011 High

    Establishing ARHGAP25 as a bona fide Rac-specific GAP answered whether this RhoGAP-family protein has genuine catalytic activity and a defined cellular role, anchoring it as a negative regulator of actin-driven phagocytosis in hematopoietic cells.

    Evidence In vitro GAP assay plus siRNA knockdown and overexpression in neutrophil model lines and primary macrophages with phagocytosis and actin readouts

    PMID:22096251

    Open questions at the time
    • Did not resolve how GAP activity is regulated in vivo
    • No structural basis for Rac specificity defined
  2. 2016 Medium

    Placing ARHGAP25 downstream of RhoE/ROCKII showed its Rac-inhibitory activity is embedded in an upstream signaling cascade and can be co-opted to promote, rather than restrain, invasion in a tumor context.

    Evidence 3D spheroid invasion assays with overexpression/knockdown and Rac activity measurements in rhabdomyosarcoma lines

    PMID:27413008

    Open questions at the time
    • Mechanism by which ROCKII regulates ARHGAP25 not defined
    • Context-dependence relative to tumor-suppressive roles unresolved
  3. 2016 High

    A knockout mouse demonstrated the in vivo physiological consequence of ARHGAP25 loss—elevated active Rac and enhanced neutrophil transendothelial migration—and showed the defect is cell-intrinsic.

    Evidence Arhgap25-knockout mice, intravital microscopy, peritonitis model, Rac-GTP pulldown, bone marrow chimeras

    PMID:27566826

    Open questions at the time
    • Upstream signals controlling ARHGAP25 during migration not identified
    • Endothelial vs leukocyte contributions only partially separated
  4. 2019 Medium

    Identification of an ARHGAP25→Wnt/β-catenin axis and a HOXA4 transcriptional input extended its role to tumor suppression and defined how its expression is controlled.

    Evidence Overexpression/knockdown in colorectal and lung cancer cells, XAV939 pharmacological rescue, ChIP and luciferase for HOXA4, in vivo metastasis xenograft

    PMID:31228451 PMID:31692494

    Open questions at the time
    • Direct molecular link between Rac inactivation and β-catenin stability not mapped
    • Generality across tumor types from single-lab studies
  5. 2020 Medium

    Phenotyping B cells in knockout mice showed ARHGAP25 governs adaptive immune cell development and chemotaxis, broadening its function beyond neutrophils to CXCR4/CXCL12-driven motility.

    Evidence Arhgap25-knockout mice, flow cytometry, germinal center analysis, CXCL12 chemotaxis assays

    PMID:32434881

    Open questions at the time
    • Whether the CXCR4 effect is Rac-mediated not directly shown
    • Single-lab characterization
  6. 2021 Medium

    A disease-associated p.G218R variant established direct causality between reduced ARHGAP25 GAP activity, elevated Rac1, and a human Mendelian phenotype (skeletal fragility).

    Evidence Exome sequencing in a three-generation family, mutant overexpression in osteosarcoma cells, structural modeling, Rac1 activity and cell morphology assays

    PMID:34258505

    Open questions at the time
    • Bone-cell-specific mechanism not demonstrated in vivo
    • Single family; penetrance and other variants not explored
  7. 2021 Medium

    Defining the Rac1/PAK1→AKT/mTOR→HIF-1α cascade revealed how ARHGAP25 loss reprograms glycolytic metabolism in cancer cells.

    Evidence Overexpression/knockdown in pancreatic adenocarcinoma cells, xenograft, glycolysis assays, PI3K/mTOR inhibitor rescue

    PMID:33994864

    Open questions at the time
    • Direct PAK1–ARHGAP25 interaction not shown
    • Single-lab pathway placement
  8. 2022 High

    Dissecting individual phosphosites distinguished which residues control catalytic GAP activity (S363, S488) versus downstream effector functions (S363, S379-380), establishing post-translational regulation of the enzyme.

    Evidence Novel real-time BRET-based GAP assay with site-directed mutagenesis plus superoxide and actin depolymerization assays in PLB-985 cells

    PMID:36190314

    Open questions at the time
    • Kinases responsible for these phosphorylations not identified
    • Stimulus-coupled phosphorylation dynamics in vivo unresolved
  9. 2023 Medium

    Knockout arthritis and breast cancer feedback studies placed ARHGAP25 in the I-κB/NF-κB/IL-1β inflammatory axis and revealed an ASCL2-mediated negative feedback loop with Wnt/β-catenin signaling.

    Evidence Arhgap25-KO arthritis model with chimeras and Western blot; breast cancer gain/loss-of-function with xenograft and bioinformatic ASCL2 binding analysis

    PMID:37234175 PMID:37326327

    Open questions at the time
    • Direct ASCL2 binding to the ARHGAP25 promoter not experimentally confirmed
    • Connection between Rac inactivation and NF-κB signaling not mechanistically resolved
  10. 2024 Medium

    Unbiased proteomic interactor mapping in neutrophils defined the GAP domain as the GTPase-binding interface and showed RAC2 and RHOG bind in an activation-state-dependent manner, identifying additional candidate partners.

    Evidence GST pulldown and reciprocal co-immunoprecipitation from neutrophil lysate with mass spectrometry and in silico dimer prediction

    PMID:39210013

    Open questions at the time
    • Functional consequences of ARF4, RAB27A, and 14-3-3 binding not tested
    • Interactions catalogued without quantitative affinities
  11. 2025 Medium

    Identifying septin2 as a positive regulator showed ARHGAP25 GAP function at lamellipodia is spatially controlled by the septin cytoskeleton, providing a mechanism for localized Rac inactivation.

    Evidence Co-immunoprecipitation, colocalization microscopy, reciprocal overexpression/depletion of ARHGAP25 and septin2, lamellipodia and cell-spreading assays

    PMID:40205813

    Open questions at the time
    • Structural basis of the septin2–ARHGAP25 interaction unknown
    • Whether septin2 regulation operates in immune-cell phenotypes in vivo not tested
  12. 2025 Medium

    A microglial RhoA conditional knockout placed Arhgap25 downstream of RhoA and upstream of HIF-1α glycolysis, extending the metabolic regulatory axis to CNS injury repair.

    Evidence Microglial RhoA conditional KO mice with single-cell and bulk RNA-seq, metabolomics, and metabolic flux assays

    PMID:40846818

    Open questions at the time
    • Direct regulation of Arhgap25 by RhoA not biochemically demonstrated
    • Microglia-specific GAP activity not measured

Open questions

Synthesis pass · forward-looking unresolved questions
  • The kinases that phosphorylate the regulatory serines, the structural basis of GTPase and septin2 recognition, and the molecular link connecting Rac inactivation to NF-κB and Wnt/β-catenin outputs remain unresolved.
  • No upstream kinase identified for S363/S488
  • No experimental structure of the ARHGAP25–GTPase or ARHGAP25–septin2 complex
  • Mechanistic coupling of Rac-GAP activity to transcriptional pathways inferred rather than direct

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0098772 molecular function regulator activity 3 GO:0008092 cytoskeletal protein binding 2
Localization
GO:0005856 cytoskeleton 2 GO:0005886 plasma membrane 1
Pathway
R-HSA-168256 Immune System 4 R-HSA-162582 Signal Transduction 3
Partners
ARF4RAB27ARAC1RAC2RHOGSEPT2

Evidence

Reading pass · 16 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2011 ARHGAP25 acts as a Rac-specific GTPase-activating protein (RacGAP) both in vitro and in vivo, and is specifically expressed in hematopoietic cells. Silencing ARHGAP25 in neutrophil model cell lines (PLB-985, CosPhoxFcγR) and overexpressing it in primary macrophages demonstrated it is a negative regulator of phagocytosis, acting via modulation of the actin cytoskeleton. In vitro GAP assay, siRNA-mediated knockdown and overexpression in neutrophil model cell lines and primary macrophages, phagocytosis assay, actin cytoskeleton analysis Blood High 22096251
2004 ARHGAP25 (KIAA0053) encodes a protein containing a Pleckstrin homology (PH) domain, a RhoGAP domain, and a C-terminal coiled-coil domain, placing it in a RhoGAP subfamily alongside ARHGAP22 and ARHGAP24. Two isoforms arise from alternative splicing/alternative promoter usage. In silico gene identification and characterization; analysis of cDNA sequences and exon-intron structure International journal of molecular medicine Low 15254788
2016 ARHGAP25 acts downstream of ROCKII in the RhoE/ROCK/ARHGAP25 signaling pathway to inhibit Rac activity and promote cell invasion in alveolar rhabdomyosarcoma (ARMS) cells. RhoE overexpression reduced invasion, and ARHGAP25 (which is upregulated in ARMS) was required for ARMS cell invasion downstream of ROCKII. 3D spheroid cell invasion assay, overexpression and knockdown experiments, Rac activity measurements, pathway epistasis analysis in ARMS and ERMS cell lines and biopsies Molecular biology of the cell Medium 27413008
2016 In Arhgap25-deficient mice, loss of ARHGAP25 leads to increased GTP-bound (active) Rac and Rac-dependent cytoskeletal changes in leukocytes, resulting in enhanced transendothelial migration of neutrophils. This phenotype was confirmed to be cell-intrinsic using bone marrow chimeric mice. Intravital microscopy, peritonitis model, in vitro chemotaxis assay, bone marrow chimeric mice, Rac-GTP pulldown, cytoskeletal analysis in Arhgap25-knockout mice Journal of immunology High 27566826
2019 ARHGAP25 overexpression in colorectal cancer (CRC) cells inhibits cell growth, migration, invasion, and suppresses Wnt/β-catenin pathway activation (reducing β-catenin, MMPs, and EMT factors). Knockdown activates the Wnt/β-catenin pathway and promotes metastasis; these effects are reversed by the Wnt inhibitor XAV939. Anti-metastatic effects were confirmed in a CRC lung metastasis xenograft model. Lentiviral overexpression, siRNA knockdown in CRC cell lines, cell proliferation/migration/invasion assays, Western blot for pathway components, XAV939 pharmacological rescue, in vivo xenograft metastasis model European journal of pharmacology Medium 31228451
2019 ARHGAP25 suppresses lung cancer cell growth, migration, and invasion through the Wnt/β-catenin signaling pathway, reducing β-catenin and MMP-7 expression. The transcription factor HOXA4 binds the ARHGAP25 promoter and regulates its transcriptional activity. Overexpression and knockdown in lung cancer cells, proliferation and Transwell migration/invasion assays, chromatin immunoprecipitation (ChIP), luciferase reporter assay, XAV939 rescue OncoTargets and therapy Medium 31692494
2021 ARHGAP25 overexpression in pancreatic adenocarcinoma cells inactivates the AKT/mTOR signaling pathway by regulating Rac1/PAK1 signaling, and reduces HIF-1α-mediated glycolysis. A dual PI3K/mTOR inhibitor (PF-04691502) reverses the increased cell growth and glycolysis caused by ARHGAP25 knockdown. Overexpression and knockdown in PAAD cell lines, in vivo xenograft, Western blot for AKT/mTOR/Rac1/PAK1/HIF-1α pathway, glycolysis assay, pharmacological rescue with PI3K/mTOR inhibitor International journal of biological sciences Medium 33994864
2021 A missense variant p.G218R in ARHGAP25 causes decreased GAP activity against Rac1, resulting in elevated Rac1 activity, increased cell spreading, and membrane ruffling. This aberrant Rac1 function is associated with early-onset autosomal-dominant skeletal fragility in a three-generation family. Exome sequencing, overexpression of ARHGAP25 G218R mutant in osteosarcoma cells, structural modeling, Rac1 activity assay, cell morphology analysis (spreading, membrane ruffling) JBMR plus Medium 34258505
2020 Arhgap25 deficiency in mice leads to decreased peripheral blood B cell numbers and defective germinal center reactions. Arhgap25-deficient B cells show increased baseline motility and augmented chemotaxis to CXCL12 in a CXCR4-dependent manner, demonstrating ARHGAP25 regulates B cell development and antigen response. Arhgap25-knockout mice, flow cytometry for B cell populations, in vitro and in vivo antigen stimulation, germinal center analysis, B cell chemotaxis assay to CXCL12 ImmunoHorizons Medium 32434881
2022 Phosphorylation of serine residues S363 and S488, but not S379-380, controls ARHGAP25's RAC-GAP activity as measured by a novel real-time BRET-based GAP assay. In contrast, superoxide production and actin depolymerization in granulocyte-differentiated PLB-985 cells are regulated by residues S363 and S379-380. Novel BRET-based GAP assay, site-directed mutagenesis of phosphorylation sites (S363, S379-380, S488), superoxide production assay, actin depolymerization assay in PLB-985 cells FASEB journal High 36190314
2022 ARHGAP25 expression negatively correlates with RhoA expression in NSCLC tissues. Lowering ARHGAP25 expression increased NSCLC cell proliferation and migration, as confirmed by colony formation, wound healing, and cytoskeleton staining assays. ARHGAP25 knockdown in NSCLC cells, colony formation assay, wound healing assay, cytoskeleton staining, immunohistochemistry in patient tissues BMC pulmonary medicine Low 36207695
2023 ARHGAP25 silencing in breast cancer cells facilitates activation of the Wnt/β-catenin pathway by directly regulating Rac1/PAK1 signaling, upregulating downstream molecules (c-Myc, Cyclin D1, PCNA, MMP2, MMP9, Snail, ASCL2). ASCL2, a Wnt/β-catenin target, transcriptionally represses ARHGAP25, forming a negative feedback loop. Knockdown and overexpression in breast cancer cell lines, in vivo xenograft, Western blot for Wnt/β-catenin pathway components, bioinformatics analysis of ASCL2 binding Carcinogenesis Medium 37326327
2023 In Arhgap25-deficient mice, autoantibody-induced arthritis severity, joint destruction, mechanical hyperalgesia, phagocyte infiltration, IL-1β, and MIP-2 levels are significantly reduced. Reduced ERK1/2, MAPK, and I-κB signals were detected in arthritic KO mouse ankles, placing ARHGAP25 in the I-κB/NF-κB/IL-1β inflammatory axis. Fibroblast-like synoviocytes express ARHGAP25 comparably to neutrophils. Arthritis induction in Arhgap25-KO and bone marrow chimeric mice, histology, leukocyte infiltration quantification, cytokine ELISA, MPO activity, superoxide production, Western blot (ERK1/2, MAPK, I-κB) Frontiers in immunology Medium 37234175
2024 Proteomic pulldown and co-immunoprecipitation from neutrophilic granulocyte lysates identified 76 candidate physical interactors of ARHGAP25. Four small GTPases (RAC2, RHOG, ARF4, RAB27A) showed high affinity; ARHGAP25-RAC2 and ARHGAP25-RHOG interactions were dependent on the GTP/GDP activation state of the GTPases. The GAP domain was identified as the binding interface. Additionally, Fc receptor-related kinases, phosphatases, and three 14-3-3 family members were identified as potential partners. GST-tag pulldown, co-immunoprecipitation from neutrophil lysate, mass spectrometry proteomics, in silico dimer prediction Scientific reports Medium 39210013
2025 Septin2, a component of the septin cytoskeleton, physically interacts with ARHGAP25 and colocalizes with it at lamellipodia in mammalian cells. Overexpression of ARHGAP25 suppresses Rac-dependent lamellipodia formation and cell spreading; this suppression is restored by depletion of septin2. Conversely, forced septin2 expression enhances ARHGAP25-mediated suppression of cell spreading, and this enhancement is abolished by ARHGAP25 depletion, demonstrating that septin2 positively regulates ARHGAP25 GAP function. Co-immunoprecipitation (interaction identification), colocalization by fluorescence microscopy, overexpression and siRNA depletion of ARHGAP25 and septin2, lamellipodia formation assay, cell spreading assay FEBS letters Medium 40205813
2025 In microglial RhoA conditional knockout mice, RhoA deficiency attenuates spinal cord injury repair and impairs microglial glycolytic metabolism (reduced glycolytic enzyme expression, ATP production, ECAR, and OCR) through the Arhgap25/HIF-1α pathway, placing Arhgap25 downstream of RhoA and upstream of HIF-1α-mediated glycolysis in microglia. Microglial RhoA conditional knockout mice, single-cell RNA sequencing, bulk RNA sequencing, metabolomics, functional assays (ECAR, OCR, ATP production) Cell death & disease Medium 40846818

Source papers

Stage 0 corpus · 20 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2011 ARHGAP25, a novel Rac GTPase-activating protein, regulates phagocytosis in human neutrophilic granulocytes. Blood 61 22096251
2004 Identification and characterization of ARHGAP24 and ARHGAP25 genes in silico. International journal of molecular medicine 51 15254788
2024 Oxygen glucose deprivation-pretreated astrocyte-derived exosomes attenuates intracerebral hemorrhage (ICH)-induced BBB disruption through miR-27a-3p /ARHGAP25/Wnt/β-catenin axis. Fluids and barriers of the CNS 34 38243347
2016 The RhoE/ROCK/ARHGAP25 signaling pathway controls cell invasion by inhibition of Rac activity. Molecular biology of the cell 32 27413008
2019 ARHGAP25: A negative regulator of colorectal cancer (CRC) metastasis via the Wnt/β-catenin pathway. European journal of pharmacology 29 31228451
2021 ARHGAP25 Inhibits Pancreatic Adenocarcinoma Growth by Suppressing Glycolysis via AKT/mTOR Pathway. International journal of biological sciences 28 33994864
2019 The tumor suppressive roles of ARHGAP25 in lung cancer cells. OncoTargets and therapy 24 31692494
2016 Rac GTPase Activating Protein ARHGAP25 Regulates Leukocyte Transendothelial Migration in Mice. Journal of immunology (Baltimore, Md. : 1950) 21 27566826
2019 Weichang'an suppressed migration and invasion of HCT116 cells by inhibiting Wnt/β-catenin pathway while upregulating ARHGAP25. Biotechnology and applied biochemistry 14 31169325
2022 Relationship between the expression of ARHGAP25 and RhoA in non-small cell lung cancer and vasculogenic mimicry. BMC pulmonary medicine 13 36207695
2021 An ARHGAP25 variant links aberrant Rac1 function to early-onset skeletal fragility. JBMR plus 12 34258505
2025 Loss of RhoA in microglia disables glycolytic adaptation and impairs spinal cord injury recovery through Arhgap25/HIF-1α pathway. Cell death & disease 10 40846818
2023 ARHGAP25 suppresses the development of breast cancer by an ARHGAP25/Wnt/ASCL2 feedback loop. Carcinogenesis 10 37326327
2023 Lacking ARHGAP25 mitigates the symptoms of autoantibody-induced arthritis in mice. Frontiers in immunology 5 37234175
2020 Arhgap25 Deficiency Leads to Decreased Numbers of Peripheral Blood B Cells and Defective Germinal Center Reactions. ImmunoHorizons 5 32434881
2022 A novel BRET-Based GAP assay reveals phosphorylation-dependent regulation of the RAC-specific GTPase activating protein ARHGAP25. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 4 36190314
2024 Neutrophil-specific interactome of ARHGAP25 reveals novel partners and regulatory insights. Scientific reports 2 39210013
2025 ARHGAP25: a novel player in the Pathomechanism of allergic contact hypersensitivity. Frontiers in immunology 1 40078992
2026 Clinical validation of PEA-driven Olink proteomic discovery: INPP1 and ARHGAP25 serum biomarkers improve early breast cancer diagnosis. Translational oncology 0 42085780
2025 Septin2 regulates ARHGAP25-mediated suppression of lamellipodia formation and cell spreading. FEBS letters 0 40205813

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