inositol-pentakisphosphate 2-kinase; IPK1 homolog; inositol-1,3,4,5,6-pentakisphosphate 2-kinase; ins(1,3,4,5,6)P5 2-kinase; insP5 2-kinase (IPPK, C9orf12)

Function

• phosphorylates Ins(1,3,4,5,6)P5 at position 2 to form Ins(1,2,3,4,5,6)P6 (InsP6 or phytate)

Kinetic parameters:

• KM=0.43 uM for ins(1,3,4,5,6)P5
• KM=21 uM for ATP
• Vmax=31 nmol/min/mg enzyme

Structure

• the EXKPK motif is conserved in inositol-pentakisphosphate 2-kinases of both family 1 & 2
• belongs to the IPK1 type 2 family

Compartment

nuclear & cytoplasmic

Expression

• ubiquitously expressed
• high expression in heart, brain, testis & placenta

More general terms

• kinase or ATP-phosphotransferase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=64768
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:64768
• UniProt: http://www.uniprot.org/uniprot/Q9H8X2.html