ITPKA
Description
The ITPKA (inositol-trisphosphate 3-kinase A) is a protein-coding gene located on chromosome 15.
ITPKA is an enzyme encoded by the ITPKA gene in humans. It belongs to the inositol polyphosphate kinase (IPK) family and is one of three inositol-trisphosphate 3-kinase (ITP3K) genes in humans. ITP3K proteins regulate inositol phosphate metabolism by phosphorylating the second messenger inositol 1,4,5-trisphosphate to produce Ins(1,3,4,5)P4 (also known as IP4). ITPKA's activity is controlled by both calcium/calmodulin and protein phosphorylation mechanisms. It is a substrate for cyclic AMP-dependent protein kinase, calcium/calmodulin-dependent protein kinase II, and protein kinase C. ITPKA shares 68% identity with ITPKB in the C-terminus region. The amino-terminal region of ITPKA binds to filamentous actin, which localizes it to dendritic spines in principal neurons. ITPKA is primarily expressed in neurons but can also be found in cancer cells, where it may contribute to metastasis.
ITPKA catalyzes the phosphorylation of 1D-myo-inositol 1,4,5-trisphosphate (InsP3) to produce 1D-myo-inositol 1,3,4,5-tetrakisphosphate, which plays a role in regulating calcium homeostasis. This function is supported by several studies (PubMed:12747803, PubMed:15350214, PubMed:1847047).
ITPKA is also known as IP3-3KA, IP3KA.
