Pik3c2a
Function
Generates phosphatidylinositol 3-phosphate (PtdIns3P) and phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) that act as second messengers. Has a role in several intracellular trafficking events. Functions in insulin signaling and secretion. Required for translocation of the glucose transporter SLC2A4/GLUT4 to the plasma membrane and glucose uptake in response to insulin-mediated RHOQ activation. Regulates insulin secretion through two different mechanisms: involved in glucose-induced insulin secretion downstream of insulin receptor in a pathway that involves AKT1 activation and TBC1D4/AS160 phosphorylation, and participates in the late step of insulin granule exocytosis probably in insulin granule fusion. Synthesizes PtdIns3P in response to insulin signaling. Functions in clathrin-coated endocytic vesicle formation and distribution. Regulates dynamin-independent endocytosis, probably by recruiting EEA1 to internalizing vesicles. In neurosecretory cells synthesizes PtdIns3P on large dense core vesicles. Participates in calcium induced contraction of vascular smooth muscle by regulating myosin light chain (MLC) phosphorylation through a mechanism involving Rho kinase-dependent phosphorylation of the MLCP-regulatory subunit MYPT1. May play a role in the EGF signaling cascade. May be involved in mitosis and UV-induced damage response. Required for maintenance of normal renal structure and function by supporting normal podocyte function. Involved in the regulation of ciliogenesis and trafficking of ciliary components (By similarity).
Post-translational modifications
Phosphorylated on Ser-261 during mitosis and upon UV irradiation; which does not change enzymatic activity but leads to proteasomal degradation (By similarity). Phosphorylated upon insulin stimulation; which may lead to enzyme activation.
Sequence Similarities
Belongs to the PI3/PI4-kinase family.
Tissue Specificity
Expressed in brain (at protein level) (PubMed:22648168). Detected in podocytes (PubMed:20974805).
Cellular localization
- Cell membrane
- Cytoplasmic vesicle
- Clathrin-coated vesicle
- Nucleus
- Cytoplasm
- Golgi apparatus
- trans-Golgi network
- Inserts preferentially into membranes containing PtdIns(4,5)P2. Associated with RNA-containing structures.
Alternative names
Cpk, Pik3c2a, Phosphatidylinositol 4-phosphate 3-kinase C2 domain-containing subunit alpha, PI3K-C2-alpha, PtdIns-3-kinase C2 subunit alpha, Cpk-m, Phosphoinositide 3-kinase-C2-alpha, p170