Ins(1,4,5)P3 metabolism and the family of IP3-3Kinases.
The release of Ca2+ from intracellular stores is triggered by the second messenger inositol (1,4,5)-trisphosphate (Ins(1,4,5)P3). The regulation of this process is critically important for cellular homeostasis. Ins(1,4,5)P3 is rapidly metabolised, either to inositol (1,4)-bisphosphate (Ins(1,4)P2) by inositol polyphosphate 5-phosphatases or to inositol (1,3,4,5)-tetrakisphosphate (Ins(1,3,4,5)P4) by one of a family of inositol (1,4,5)P3 3-kinases (IP3-3Ks). Three isoforms of IP3-3K have now been identified in mammals; they have a conserved C-terminal catalytic domain, but divergent N-termini. This review discusses the metabolism of Ins(1,4,5)P3, compares the IP3-3K isoforms and addresses potential mechanisms by which their activity might be regulated.
Pattni
Krupa
K
Department of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK.
Banting
George
G
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism; D000072181:Inositol Polyphosphate 5-Phosphatases; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
D007295:Inositol Phosphates; C081655:inositol-1,3,4,5-tetrakisphosphate; D015544:Inositol 1,4,5-Trisphosphate; D017853:Phosphotransferases (Alcohol Group Acceptor); C051038:Inositol 1,4,5-trisphosphate 3-kinase; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases; D002118:Calcium