Diphosphoinositol pentakisphosphate kinase 2 (PPIP5K2)

Diphosphoinositol pentakisphosphate kinase 2 (PPIP5K2) is a bifunctional kinase enzyme in humans responsible for synthesizing inositol pyrophosphates such as InsP7 and InsP8, which are high-energy signaling molecules that regulate a broad range of cellular processes, including apoptosis, vesicle trafficking, cytoskeletal organization, exocytosis, insulin signaling, and immune cell function[1][3][4][5]. PPIP5K2 acts at the interface of cellular signaling and energy metabolism, displaying a unique ATP-grasp kinase fold and containing a histidine acid phosphatase domain, although it lacks phosphatase activity[2][5]. Mutations in PPIP5K2 are linked to rare forms of autosomal recessive non-syndromic sensorineural deafness, and genomic data suggest potential involvement in autism spectrum disorder[5]. There are currently no clinically approved drugs directly targeting PPIP5K2, but its essential homeostatic and signaling roles make it of interest as a regulatory enzyme in disease contexts.

Other names

Inositol hexakisphosphate and diphosphoinositol-pentakisphosphate kinase 2HISPPD1KIAA0433VIP2hsVIP2CFAP160InsP6 and PP-IP5 kinase 2VIP1 homolog 2IP7K2Deafness, autosomal recessive 100 (DFNB100)Histidine acid phosphatase domain-containing protein 1Inositol heptaphosphate kinase 2

Kinase inhibition (theoretical, as no direct therapeutic inhibitors appear to be clinically established) or modulation of inositol pyrophosphate synthesis (mechanism inferred from enzymatic role).