PPIP5K2
Domain
The C-terminal acid phosphatase-like domain binds PtdIns(3,4,5)P3 and InsP6. Despite its similarity with the phosphatase domain of histidine acid phosphatases, it has no phosphatase activity.
Function
Bifunctional inositol kinase that acts in concert with the IP6K kinases IP6K1, IP6K2 and IP6K3 to synthesize the diphosphate group-containing inositol pyrophosphates diphosphoinositol pentakisphosphate, PP-InsP5, and bis-diphosphoinositol tetrakisphosphate, (PP)2-InsP4 (PubMed:17690096, PubMed:17702752, PubMed:21222653, PubMed:29590114). PP-InsP5 and (PP)2-InsP4, also respectively called InsP7 and InsP8, regulate a variety of cellular processes, including apoptosis, vesicle trafficking, cytoskeletal dynamics, exocytosis, insulin signaling and neutrophil activation (PubMed:17690096, PubMed:17702752, PubMed:21222653, PubMed:29590114). Phosphorylates inositol hexakisphosphate (InsP6) at position 1 to produce PP-InsP5 which is in turn phosphorylated by IP6Ks to produce (PP)2-InsP4 (PubMed:17690096, PubMed:17702752). Alternatively, phosphorylates PP-InsP5 at position 1, produced by IP6Ks from InsP6, to produce (PP)2-InsP4 (PubMed:17690096, PubMed:17702752). Required for normal hearing (PubMed:29590114).
Involvement in disease
Deafness, autosomal recessive, 100
DFNB100
A form of non-syndromic, sensorineural deafness characterized by prelingual hearing impairment. Sensorineural deafness results from damage to the neural receptors of the inner ear, the nerve pathways to the brain, or the area of the brain that receives sound information.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the histidine acid phosphatase family. VIP1 subfamily.
Cellular localization
- Cytoplasm
- Cytosol
Alternative names
HISPPD1, KIAA0433, VIP2, PPIP5K2, Inositol hexakisphosphate and diphosphoinositol-pentakisphosphate kinase 2, Diphosphoinositol pentakisphosphate kinase 2, Histidine acid phosphatase domain-containing protein 1, InsP6 and PP-IP5 kinase 2, VIP1 homolog 2, hsVIP2