FEATURES

FAMILY

DESCRIPTION

Also known as IPMK_YEAST, ARG82, ARGR3, GSL3, IPK2. Inositol phosphate kinase with both monophosphoinositol and diphosphoinositol polyphosphate synthase activities. Able to phosphorylate inositol 1, 4, 5-trisphosphate (Ins(1, 4, 5)P3) on both the carbon-3 and carbon-6 positions to synthesize inositol 1, 3, 4, 5-tetrakisphosphate (Ins(1, 3, 4, 5)P4) and inositol 1, 4, 5, 6-tetrakisphosphate (Ins(1, 4, 5, 6)P4), and then to subsequently phosphorylate and convert either isomer of InsP4 to inositol 1, 3, 4, 5, 6-pentakisphosphate (Ins(1, 3, 4, 5, 6)P5) (PubMed:10574768, PubMed:10683435, PubMed:11311242). Its predominant in vivo catalytic function is to convert Ins(1, 4, 5)P3 to Ins(1, 4, 5, 6)P4 to Ins(1, 3, 4, 5, 6)P5 via 6- and 3-kinase activities (PubMed:15944147). It can also use Ins(1, 3, 4, 5, 6)P5 as a substrate and act as a diphosphoinositol polyphosphate synthase to generate two different isomers of PP-InsP4 (PubMed:11311242). Has also a role in transcription regulation. Forms a complex with ARG80, ARG81 and MCM1 (ArgR-MCM1), which coordinates the expression of arginine anabolic and catabolic genes in response to arginine. Recruits ARG80 and MCM21 to stabilize them (PubMed:3298999, PubMed:8043104, PubMed:10632874). Neither the kinase activity nor inositol phosphates are required for the formation of ArgR-MCM1 transciptional complexes on DNA promoter elements and the control of arginine metabolism (PubMed:11119723, PubMed:10720331, PubMed:12828642, PubMed:22992733). In contrast, only the catalytic activity is required for PHO gene repression by phosphate and for NCR gene activation in response to nitrogen availability, indicating a role for inositol pyrophosphates in these controls (PubMed:12828642). Inositol polyphosphates may be involved in the regulation of chromatin remodeling of transcription (PubMed:12434012). Regulates nuclear mRNA export via inositol phosphate metabolism (PubMed:10390371, PubMed:10683435). Also has lipid kinase activity, transforming the lipid inositol phosphatidylinositol 4, 5-bisphosphate (PI(4, 5)P2) into phosphatidylinositol 3, 4, 5-trisphosphate (PI(3, 4, 5)P3) in the nucleus (PubMed:16123124). Its kinase activity is necessary for the propagation of most [PSI+] prion variants (PubMed:28923943). Interacts with ARG80 and MCM1.

Also known as IPMK_YEAST, ARG82, ARGR3, GSL3, IPK2. Inositol phosphate kinase with both monophosphoinositol and diphosphoinositol polyphosphate synthase activities. Able to phosphorylate inositol ...

EXTERNAL LINKS

ARG82

Inositol polyphosphate multikinase

ARG82

Molecular Synopsis