ITPKB

Inositol-trisphosphate 3-kinase B is an enzyme that in humans is encoded by the ITPKB gene.[5][6]

ITPKB
Identifiers
Aliases	ITPKB, IP3-3KB, IP3K, IP3K-B, IP3KB, PIG37, inositol-trisphosphate 3-kinase B
External IDs	OMIM: 147522 MGI: 109235 HomoloGene: 1672 GeneCards: ITPKB
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1q42.12 Start 226,631,690 bp[1] End 226,739,323 bp[1]
Gene location (Mouse) Chr. Chromosome 1 (mouse)[2] Band 1 H4|1 84.27 cM Start 180,330,485 bp[2] End 180,424,802 bp[2]
RNA expression pattern More reference expression data
Gene ontology Molecular function • transferase activity • nucleotide binding • calmodulin binding • kinase activity • GO:0001948 protein binding • ATP binding • inositol-1,4,5-trisphosphate 3-kinase activity Cellular component • cytosol • membrane • cell nucleus Biological process • regulation of protein phosphorylation • cellular response to calcium ion • negative regulation of neutrophil apoptotic process • phosphorylation • common myeloid progenitor cell proliferation • myeloid cell homeostasis • positive regulation of Ras protein signal transduction • inositol phosphate metabolic process • inositol trisphosphate metabolic process • MAPK cascade • cell surface receptor signaling pathway • T cell differentiation • positive thymic T cell selection • negative regulation of myeloid cell differentiation • positive regulation of alpha-beta T cell differentiation • thymic T cell selection • signal transduction • inositol phosphate biosynthetic process Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	3707	320404
Ensembl	ENSG00000143772	ENSMUSG00000038855
UniProt	P27987	B2RXC2
RefSeq (mRNA)	NM_002221	NM_001081175
RefSeq (protein)	NP_002212	NP_001074644
Location (UCSC)	Chr 1: 226.63 – 226.74 Mb	Chr 1: 180.33 – 180.42 Mb
PubMed search	[3]	[4]
Wikidata
View/Edit Human View/Edit Mouse

Function

The protein encoded by the ITPKB gene is one of 3 isoforms of Inositol-trisphosphate 3-kinase expressed in humans. ITPKB protein regulates inositol phosphate metabolism by phosphorylation of second messenger inositol 1,4,5-trisphosphate, which releases calcium from intracellular store in the endoplasmic reticulum by gating the inositol trisphosphate receptor. ITPKB produces Ins(1,3,4,5)P4, which does not gate the inositol trisphosphate receptor. The enzyme specifically phosphorylates the 1,4,5 isomer of IP3. The activity of this encoded protein is responsible for regulating the levels of a large number of inositol polyphosphates that are important in cellular signaling. Both calcium/calmodulin and protein phosphorylation mechanisms control its activity.[7] Itpkb regulates immune cell function and is required for T and B cell development.[8]

References

1. GRCh38: Ensembl release 89: ENSG00000143772 - Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000038855 - Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Takazawa K, Perret J, Dumont JE, Erneux C (Oct 1991). "Molecular cloning and expression of a new putative inositol 1,4,5-trisphosphate 3-kinase isoenzyme". Biochem J. 278 (3): 883–6. doi:10.1042/bj2780883. PMC 1151429. PMID 1654894.
6. Erneux C, Roeckel N, Takazawa K, Mailleux P, Vassart G, Mattei MG (Dec 1992). "Localization of the genes for human inositol 1,4,5-trisphosphate 3-kinase A (ITPKA) and B (ITPKB) to chromosome regions 15q14-q21 and 1q41-q43, respectively, by in situ hybridization". Genomics. 14 (2): 546–7. doi:10.1016/S0888-7543(05)80265-4. PMID 1330886.
7. "Entrez Gene: ITPKB inositol 1,4,5-trisphosphate 3-kinase B".
8. Sauer K, Cooke MP (April 2010). "Regulation of immune cell development through soluble inositol-1,3,4,5-tetrakisphosphate". Nat. Rev. Immunol. 10 (4): 257–71. doi:10.1038/nri2745. PMC 2922113. PMID 20336153.

Further reading

• Szlufcik K, Missiaen L, Parys JB, et al. (2006). "Uncoupled IP3 receptor can function as a Ca2+-leak channel: cell biological and pathological consequences". Biol. Cell. 98 (1): 1–14. doi:10.1042/BC20050031. PMID 16354157.