PIK3R2 : phosphoinositide-3-kinase regulatory subunit 2
Description
The PIK3R2 (phosphoinositide-3-kinase regulatory subunit 2) is a protein-coding gene located on chromosome 19.
The PIK3R2 gene provides instructions for making a subunit of the phosphatidylinositol 3-kinase (PI3K) enzyme called P85β. P85β regulates PI3K activity, which is a kinase that adds a phosphate group to other proteins. This phosphorylation process triggers reactions in the PI3K-AKT-mTOR pathway, influencing essential cell functions like protein synthesis, cell growth and division, and cell survival. This pathway is vital for the normal development of various body parts, including the brain.
PIK3R2 is a regulatory subunit of the PI3K enzyme, a kinase that adds a phosphate group to phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) to create phosphatidylinositol 3,4,5-trisphosphate (PIP3). PIP3 is crucial for recruiting proteins with PH domains to the cell membrane, including AKT1 and PDPK1, which activate signaling pathways controlling cell growth, survival, proliferation, movement, and shape. PIK3R2 interacts with activated protein-tyrosine kinases through its SH2 domain and acts as an adaptor, linking the p110 catalytic unit to the cell membrane. It indirectly regulates autophagy and promotes the movement of XBP1 isoform 2 into the nucleus during metabolic stress in the liver, which contributes to improved glucose tolerance.
PIK3R2 is also known as MPPH, MPPH1, P85B, p85, p85-BETA, p85beta.
Associated Diseases
- Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus syndrome
- Megalencephaly-polymicrogyria-postaxial polydactyly-hydrocephalus syndrome
- Megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome
