Phosphatase Subfamily PPIP5K

Phosphatase Classification: Fold HP: Superfamily HP (histidine phosphatase): Family HP, branch 2: PPIP5K

Evolution

PPIP5K is conserved across opisthokont. Human genome has three copies.

Functions

This gene encodes a dual functional inositol kinase. The encoded enzyme converts inositol hexakisphosphate to diphosphoinositol pentakisphosphate and diphosphoinositol pentakisphosphate to bis-diphosphoinositol tetrakisphosphate. This protein may be important for intracellular signaling pathways.

Inositol phosphates (IPs) and diphosphoinositol phosphates (PP-IPs), also known as inositol pyrophosphates, act as cell signaling molecules. HISPPD1 has both IP6 kinase (EC 2.7.4.21) and PP-IP5 (also called IP7) kinase (EC 2.7.4.24) activities that produce the high-energy pyrophosphates PP-IP5 and PP2-IP4 (also called IP8), respectively (Fridy et al., 2007 [PubMed 17690096])