ARHGEF6

Last updated
ARHGEF6
Protein ARHGEF6 PDB 1ujy.png
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases ARHGEF6 , COOL2, Cool-2, MRX46, PIXA, alpha-PIX, alphaPIX, Rac/Cdc42 guanine nucleotide exchange factor 6
External IDs OMIM: 300267 MGI: 1920591 HomoloGene: 3561 GeneCards: ARHGEF6
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001306177
NM_004840

NM_152801
NM_001358573

RefSeq (protein)

NP_001293106
NP_004831

Location (UCSC) Chr X: 136.67 – 136.78 Mb Chr X: 57.23 – 57.34 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Rho guanine nucleotide exchange factor 6 is a protein that, in humans, is encoded by the ARHGEF6 gene. [5] [6] [7]

ARHGEF6 is commonly known as the p21-activated protein kinase exchange factor alpha (alpha-PIX or αPIX), because it was identified by binding to p21-activated kinase (PAK) and also contains a guanine nucleotide exchange factor domain. [6]

Domains and functions

αPIX is a multidomain protein that functions both as a signaling scaffold protein and as an enzyme. [8] αPIX shares this domain structure and signaling function with the highly similar ARHGEF7/βPIX protein. αPIX contains a central DH/PH RhoGEF domain that functions as a guanine nucleotide exchange factor (GEF) for small GTPases of the Rho family, and specifically Rac and Cdc42. [6] Like other GEFs, αPIX can promote both release of GDP from an inactive small GTP-binding protein and binding of GTP to promote its activation. Signaling scaffolds bind to specific partners to promote efficient signal transduction by arranging sequential elements of a pathway near each other to facilitate interaction/information transfer, and also by holding these partner protein complexes in specific locations within the cell to promote local or regional signaling. In the case of αPIX, its SH3 domain binds to partner proteins with appropriate polyproline motifs, and particularly to group I p21-activated kinases (PAKs) (PAK1, PAK2 and PAK3). [6] PAK is bound to the αPIX SH3 domain in the inactive state, and activated Rac1 or Cdc42 binding to this PAK stimulates its protein kinase activity leading to downstream target protein phosphorylation; since αPIX can activate the “p21’’ small GTPases Rac1 or Cdc42 through its GEF activity, this αPIX/PAK/Rac complex exemplifies a scaffolding function. Structurally, αPIX assembles as a trimer through its carboxyl-terminal coiled-coil domain, and further interacts with dimers of GIT1 or GIT2 through a nearby GIT-binding domain to form oligomeric GIT-PIX complexes. [8] Through this GIT-PIX complex, the scaffolding function of αPIX is amplified by also being able to hold GIT partners in proximity to αPIX partners. αPIX contains an amino-terminal Calponin Homology (CH) domain whose functions remain relatively poorly defined, but interacts with parvin/affixin family proteins. [9] [8]

Because the ARHGEF6 gene is located on the X chromosome so that males have only one copy, mutations in this gene in humans can cause X-chromosome-linked non-specific intellectual disability, [10] as can mutations affecting its binding partner PAK3 whose gene is also located on the X chromosome. [11] In animal models, loss of ARHGEF6 gene function is associated with neuronal synapse defects, [12] immune T-cell migration and maturation defects, [13] and hearing loss. [14]

Interactions

αPIX has been reported to interact with over 40 proteins. [8] [15]

Major interacting proteins include:

See also

Related Research Articles

GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a protein domain common to many GTPases.

<span class="mw-page-title-main">Guanine nucleotide exchange factor</span> Proteins which remove GDP from GTPases

Guanine nucleotide exchange factors (GEFs) are proteins or protein domains that activate monomeric GTPases by stimulating the release of guanosine diphosphate (GDP) to allow binding of guanosine triphosphate (GTP). A variety of unrelated structural domains have been shown to exhibit guanine nucleotide exchange activity. Some GEFs can activate multiple GTPases while others are specific to a single GTPase.

<span class="mw-page-title-main">FGD1</span> Protein-coding gene in the species Homo sapiens

FYVE, RhoGEF and PH domain-containing protein 1 (FGD1) also known as faciogenital dysplasia 1 protein (FGDY), zinc finger FYVE domain-containing protein 3 (ZFYVE3), or Rho/Rac guanine nucleotide exchange factor FGD1 is a protein that in humans is encoded by the FGD1 gene that lies on the X chromosome. Orthologs of the FGD1 gene are found in dog, cow, mouse, rat, and zebrafish, and also budding yeast and C. elegans. It is a member of the FYVE, RhoGEF and PH domain containing family.

<span class="mw-page-title-main">Transforming protein RhoA</span> Protein and coding gene in humans

Transforming protein RhoA, also known as Ras homolog family member A (RhoA), is a small GTPase protein in the Rho family of GTPases that in humans is encoded by the RHOA gene. While the effects of RhoA activity are not all well known, it is primarily associated with cytoskeleton regulation, mostly actin stress fibers formation and actomyosin contractility. It acts upon several effectors. Among them, ROCK1 and DIAPH1 are the best described. RhoA, and the other Rho GTPases, are part of a larger family of related proteins known as the Ras superfamily, a family of proteins involved in the regulation and timing of cell division. RhoA is one of the oldest Rho GTPases, with homologues present in the genomes since 1.5 billion years. As a consequence, RhoA is somehow involved in many cellular processes which emerged throughout evolution. RhoA specifically is regarded as a prominent regulatory factor in other functions such as the regulation of cytoskeletal dynamics, transcription, cell cycle progression and cell transformation.

<span class="mw-page-title-main">T-cell lymphoma invasion and metastasis-inducing protein 1</span> Protein-coding gene in the species Homo sapiens

Rho guanine nucleotide exchange factor TIAM1 is a protein that in humans is encoded by the TIAM1 gene.

<span class="mw-page-title-main">RhoGEF domain</span>

RhoGEF domain describes two distinct structural domains with guanine nucleotide exchange factor (GEF) activity to regulate small GTPases in the Rho family. Rho small GTPases are inactive when bound to GDP but active when bound to GTP; RhoGEF domains in proteins are able to promote GDP release and GTP binding to activate specific Rho family members, including RhoA, Rac1 and Cdc42.

<span class="mw-page-title-main">ARHGEF7</span> Protein-coding gene in the species Homo sapiens

Rho guanine nucleotide exchange factor 7 is a protein that in humans is encoded by the ARHGEF7 gene.

<span class="mw-page-title-main">AKAP13</span> Protein-coding gene in the species Homo sapiens

A-kinase anchor protein 13 is a protein that in humans, is encoded by the AKAP13 gene. This protein is also called AKAP-Lbc because it encodes the lymphocyte blast crisis (Lbc) oncogene, and ARHGEF13/RhoGEF13 because it contains a guanine nucleotide exchange factor (GEF) domain for the RhoA small GTP-binding protein.

<span class="mw-page-title-main">PLXNB1</span> Protein-coding gene in the species Homo sapiens

Plexin B1 is a protein of the plexin family that in humans is encoded by the PLXNB1 gene.

<span class="mw-page-title-main">ARHGEF1</span> Protein-coding gene in the species Homo sapiens

Rho guanine nucleotide exchange factor 1 is a protein that in humans is encoded by the ARHGEF1 gene. This protein is also called RhoGEF1 or p115-RhoGEF.

<span class="mw-page-title-main">ARHGEF2</span> Mammalian protein found in Homo sapiens

Rho guanine nucleotide exchange factor 2 is a protein that in humans is encoded by the ARHGEF2 gene.

<span class="mw-page-title-main">ARHGEF11</span> Protein-coding gene in the species Homo sapiens

Rho guanine nucleotide exchange factor 11 is a protein that in humans is encoded by the ARHGEF11 gene. This protein is also called RhoGEF11 or PDZ-RhoGEF.

<span class="mw-page-title-main">ARHGEF12</span> Protein-coding gene in the species Homo sapiens

Rho guanine nucleotide exchange factor 12 is a protein that in humans is encoded by the ARHGEF12 gene. This protein is also called RhoGEF12 or Leukemia-associated Rho guanine nucleotide exchange factor (LARG).

<span class="mw-page-title-main">RhoG</span> Protein-coding gene in the species Homo sapiens

RhoG is a small monomeric GTP-binding protein, and is an important component of many intracellular signalling pathways. It is a member of the Rac subfamily of the Rho family of small G proteins and is encoded by the gene RHOG.

<span class="mw-page-title-main">TRIO (gene)</span> Protein-coding gene in the species Homo sapiens

Triple functional domain protein is a protein that in humans is encoded by the TRIO gene.

<span class="mw-page-title-main">VAV3</span> Protein-coding gene in the species Homo sapiens

Guanine nucleotide exchange factor VAV3 is a protein that in humans is encoded by the VAV3 gene.

<span class="mw-page-title-main">Dedicator of cytokinesis protein 4</span> Protein-coding gene in the species Homo sapiens

Dedicator of cytokinesis protein 4 (Dock4), is a large protein encoded in the human by the DOCK4 gene, involved in intracellular signalling networks. It is a member of the DOCK-B subfamily of the DOCK family of guanine nucleotide exchange factors (GEFs) which function as activators of small G-proteins. Dock4 activates the small G proteins Rac and Rap1.

<span class="mw-page-title-main">GNA13</span> Protein-coding gene in the species Homo sapiens

Guanine nucleotide-binding protein subunit alpha-13 is a protein that in humans is encoded by the GNA13 gene.

<span class="mw-page-title-main">GNA12</span> Protein-coding gene in the species Homo sapiens

Guanine nucleotide-binding protein subunit alpha-12 is a protein that in humans is encoded by the GNA12 gene.

<span class="mw-page-title-main">PLEKHG2</span> Protein-coding gene in the species Homo sapiens

Pleckstrin homology domain containing, family G member 2 (PLEKHG2) is a protein that in humans is encoded by the PLEKHG2 gene. It is sometimes written as ARHGEF42, FLJ00018.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000129675 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000031133 - Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Nomura N, Nagase T, Miyajima N, Sazuka T, Tanaka A, Sato S, Seki N, Kawarabayasi Y, Ishikawa K, Tabata S (Dec 1995). "Prediction of the coding sequences of unidentified human genes. II. The coding sequences of 40 new genes (KIAA0041-KIAA0080) deduced by analysis of cDNA clones from human cell line KG-1 (supplement)". DNA Res. 1 (5): 251–62. doi: 10.1093/dnares/1.5.251 . PMID   7584048.
  6. 1 2 3 4 Manser E, Loo TH, Koh CG, Zhao ZS, Chen XQ, Tan L, Tan I, Leung T, Lim L (Jul 1998). "PAK kinases are directly coupled to the PIX family of nucleotide exchange factors". Mol Cell. 1 (2): 183–92. doi: 10.1016/S1097-2765(00)80019-2 . PMID   9659915.
  7. "Entrez Gene: ARHGEF6 Rac/Cdc42 guanine nucleotide exchange factor (GEF) 6".
  8. 1 2 3 4 Zhou W, Li X, Premont RT (May 2016). "Expanding functions of GIT Arf GTPase-activating proteins, PIX Rho guanine nucleotide exchange factors and GIT-PIX complexes". Journal of Cell Science. 129 (10): 1963–1974. doi:10.1242/jcs.179465. PMC   6518221 . PMID   27182061.
  9. Rosenberger G, Jantke I, Gal A, Kutsche K (2003). "Interaction of alphaPIX (ARHGEF6) with beta-parvin (PARVB) suggests an involvement of alphaPIX in integrin-mediated signaling". Human Molecular Genetics. 12 (2): 155–167. doi: 10.1093/hmg/ddg019 . PMID   12499396.
  10. Kutsche K, Yntema H, Brandt A, Jantke I, Nothwang HG, Orth U, Boavida MG, David D, Chelly J, Fryns JP, Moraine C, Ropers HH, Hamel BC, van Bokhoven H, Gal A (2000). "Mutations in ARHGEF6, encoding a guanine nucleotide exchange factor for Rho GTPases, in patients with X-linked mental retardation". Nature Genetics. 26 (2): 247–250. doi:10.1038/80002. PMID   11017088. S2CID   12325765.
  11. Allen KM, Gleeson JG, Bagrodia S, Partington MW, MacMillan JC, Cerione RA, Mulley JC, Walsh CA (September 1998). "PAK3 mutation in nonsyndromic X-linked mental retardation". Nature Genetics. 20 (1): 25–30. doi:10.1038/1675. PMID   9731525. S2CID   16041444.
  12. Ramakers GJ, Wolfer D, Rosenberger G, Kuchenbecker K, Kreienkamp HJ, Prange-Kiel J, Rune G, Richter K, Langnaese K, Masneuf S, Bösl MR, Fischer KD, Krugers HJ, Lipp HP, van Galen E, Kutsche K (January 2012). "Dysregulation of Rho GTPases in the αPix/Arhgef6 mouse model of X-linked intellectual disability is paralleled by impaired structural and synaptic plasticity and cognitive deficits" (PDF). Human Molecular Genetics. 21 (2): 268–286. doi:10.1093/hmg/ddr457. hdl: 20.500.11850/41564 . PMID   21989057.
  13. Korthals M, Schilling K, Reichardt P, Mamula D, Schlüter T, Steiner M, Langnäse K, Thomas U, Gundelfinger E, Premont RT, Tedford K, Fischer KD (April 2014). "αPIX RhoGEF supports positive selection by restraining migration and promoting arrest of thymocytes". Journal of Immunology. 192 (7): 3228–3238. doi: 10.4049/jimmunol.1302585 . PMID   24591366.
  14. Zhu C, Cheng C, Wang Y, Muhammad W, Liu S, Zhu W, Shao B, Zhang Z, Yan X, He Q, Xu Z, Yu C, Qian X, Lu L, Zhang S, Zhang Y, Xiong W, Gao X, Xu Z, Chai R (October 2018). "Loss of ARHGEF6 Causes Hair Cell Stereocilia Deficits and Hearing Loss in Mice". Frontiers in Molecular Neuroscience. 11: 362. doi: 10.3389/fnmol.2018.00362 . PMC   6176010 . PMID   30333726.
  15. "ARHGEF6 Result Summary".

Further reading