ID:PAK3_HUMAN DESCRIPTION: RecName: Full=Serine/threonine-protein kinase PAK 3; EC=2.7.11.1; AltName: Full=Beta-PAK; AltName: Full=Oligophrenin-3; AltName: Full=p21-activated kinase 3; Short=PAK-3; FUNCTION: Serine/threonine protein kinase that plays a role in a variety of different signaling pathways including cytoskeleton regulation, cell migration, or cell cycle regulation. Plays a role in dendrite spine morphogenesis as well as synapse formation and plasticity. Acts as downstream effector of the small GTPases CDC42 and RAC1. Activation by the binding of active CDC42 and RAC1 results in a conformational change and a subsequent autophosphorylation on several serine and/or threonine residues. Phosphorylates MAPK4 and MAPK6 and activates the downstream target MAPKAPK5, a regulator of F-actin polymerization and cell migration. Additionally, phosphorylates TNNI3/troponin I to modulate calcium sensitivity and relaxation kinetics of thin myofilaments. CATALYTIC ACTIVITY: ATP + a protein = ADP + a phosphoprotein. COFACTOR: Magnesium (By similarity). ENZYME REGULATION: Activated by binding small G proteins. Binding of GTP-bound CDC42 or RAC1 to the autoregulatory region releases monomers from the autoinhibited dimer, enables phosphorylation of Thr-436 and allows the kinase domain to adopt an active structure (By similarity). SUBUNIT: Interacts tightly with GTP-bound but not GDP-bound CDC42/p21 and RAC1. Shows highly specific binding to the SH3 domains of phospholipase C-gamma and of adapter protein NCK. Interacts with the C-terminal of APP (By similarity). Interacts with ARHGEF6 and ARHGEF7. INTERACTION: P60953-2:CDC42; NbExp=2; IntAct=EBI-3389553, EBI-287394; P63000:RAC1; NbExp=2; IntAct=EBI-3389553, EBI-413628; SUBCELLULAR LOCATION: Cytoplasm (By similarity). TISSUE SPECIFICITY: Restricted to the nervous system. Highly expressed in postmitotic neurons of the developing and postnatal cerebral cortex and hippocampus. PTM: Autophosphorylated when activated by CDC42/p21. DISEASE: Defects in PAK3 are the cause of mental retardation X- linked type 30 (MRX30) [MIM:300558]; also called X-linked mental retardation type 47 (MRX47). Mental retardation is a mental disorder characterized by significantly sub-average general intellectual functioning associated with impairments in adaptative behavior and manifested during the developmental period. Non- syndromic mental retardation patients do not manifest other clinical signs. SIMILARITY: Belongs to the protein kinase superfamily. STE Ser/Thr protein kinase family. STE20 subfamily. SIMILARITY: Contains 1 CRIB domain. SIMILARITY: Contains 1 protein kinase domain. WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/PAK3";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
Pfam Domains: PF00069 - Protein kinase domain PF00786 - P21-Rho-binding domain PF07714 - Protein tyrosine and serine/threonine kinase
SCOP Domains: 56112 - Protein kinase-like (PK-like)
ModBase Predicted Comparative 3D Structure on O75914
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
