PIK3R5

Phosphatidylinositol 3-kinases (PI3Ks) phosphorylate the inositol ring of phosphatidylinositol at the 3-prime position, and play important roles in cell growth, proliferation, differentiation, motility, survival and intracellular trafficking. The PI3Ks are divided into three classes: I, II and III, and only the class I PI3Ks are involved in oncogenesis. This gene encodes the 101 kD regulatory subunit of the class I PI3K gamma complex, which is a dimeric enzyme, consisting of a 110 kD catalytic subunit gamma and a regulatory subunit of either 55, 87 or 101 kD. This protein recruits the catalytic subunit from the cytosol to the plasma membrane through high-affinity interaction with G-beta-gamma proteins. Multiple alternatively spliced transcript variants encoding two distinct isoforms have been found. [provided by RefSeq, Oct 2011]

Full Name

Phosphoinositide-3-Kinase Regulatory Subunit 5

Function

Regulatory subunit of the PI3K gamma complex. Required for recruitment of the catalytic subunit to the plasma membrane via interaction with beta-gamma G protein dimers. Required for G protein-mediated activation of PIK3CG (By similarity).

Biological Process

G protein-coupled receptor signaling pathwayISS:UniProtKB
Immune response1 PublicationIC:ComplexPortal
Phosphatidylinositol 3-kinase signalingISS:UniProtKB
Positive regulation of MAP kinase activityISS:UniProtKB
Positive regulation of protein kinase B signalingISS:UniProtKB

Cellular Location

Nucleus
Cytoplasm
Cell membrane
Predominantly localized in the nucleus in absence of PIK3CG/p120. Colocalizes with PIK3CG/p120 in the cytoplasm. Translocated to the plasma membrane in a beta-gamma G protein-dependent manner.

Involvement in disease

Ataxia-oculomotor apraxia 3 (AOA3):
An autosomal recessive disease characterized by cerebellar ataxia, oculomotor apraxia, areflexia and peripheral neuropathy.