Inositol Hexaphosphate Kinase 1 (IHPK1)

Inositol hexakisphosphate kinase 1 is a protein that belongs to the inositol phosphokinase (IPK) family. This protein is likely responsible for the conversion of inositol hexakisphosphate (InsP6) to diphosphoinositol pentakisphosphate (InsP7/PP-InsP5). It may also convert 1,3,4,5,6-pentakisphosphate (InsP5) to PP-InsP4. Alternative splicing occurs for this gene; however, the full-length nature of all transcript variants has not yet been described.By comparison with rat Ihpk1 and database searching, Saiardi et al. (1999) identified mouse Ihpk1, which is 97% homologous to KIAA0263. Western blot analysis showed expression of a 50-kD protein. Northern blot analysis revealed expression of a 5.0-kb transcript in mouse brain and testis, with much lower levels in heart, liver, kidney, lung, and spleen.