FEATURES

FAMILY

DESCRIPTION

Also known as ITPK1_MAIZE, ITPK1, LPA2. Kinase that can phosphorylate various inositol polyphosphate such as Ins(3, 4, 5, 6)P4 or Ins(1, 3, 4)P3 and participates in phytic acid biosynthesis in developing seeds. Phosphorylates Ins(3, 4, 5, 6)P4 at position 1 to form Ins(1, 3, 4, 5, 6)P5. This reaction is thought to have regulatory importance, since Ins(3, 4, 5, 6)P4 is an inhibitor of plasma membrane Ca(2+)-activated Cl(-) channels, while Ins(1, 3, 4, 5, 6)P5 is not. Also phosphorylates Ins(1, 3, 4)P3 on O-5 and O-6 to form Ins(1, 3, 4, 6)P4, an essential molecule in the hexakisphosphate (InsP6) pathway. Also able to phosphorylate Ins(3, 5, 6)P3 but not Ins(1, 4, 5)P3, Ins(2, 4, 5)P3, Ins(1, 3, 4, 6)P4 nor Ins(1, 3, 5, 6)P4. Has higher specific activity on Ins(3, 4, 5, 6)P4 than Ins(1, 3, 4)P3 and Ins(3, 5, 6)P3. Can also could use Ins(1, 2, 5, 6)P4 as a substrate. Monomer.

EXTERNAL LINKS

ITPK1

Inositol-tetrakisphosphate 1-kinase 1

ITPK1

Molecular Synopsis