ITPKA

Inositol-trisphosphate 3-kinase A is an enzyme that in humans is encoded by the ITPKA gene.^[5][6][7]

ITPKA
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1W2C, 1W2D, 1W2F, 4UPU
Identifiers
Aliases	ITPKA, IP3-3KA, IP3KA, inositol-trisphosphate 3-kinase A
External IDs	OMIM: 147521; MGI: 1333822; HomoloGene: 1671; GeneCards: ITPKA; OMA:ITPKA - orthologs
Gene location (Human) Chr. Chromosome 15 (human)[1] Band 15q15.1 Start 41,493,393 bp[1] End 41,503,551 bp[1]
Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2|2 E5 Start 119,572,818 bp[2] End 119,581,744 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in mucosa of transverse colon right frontal lobe Brodmann area 9 prefrontal cortex middle temporal gyrus caudate nucleus putamen cingulate gyrus anterior cingulate cortex nucleus accumbens Top expressed in Region I of hippocampus proper hippocampus proper primary visual cortex prefrontal cortex superior frontal gyrus dentate gyrus of hippocampal formation granule cell dorsal striatum Temporal Lobe nucleus accumbens Amygdala More reference expression data BioGPS More reference expression data
Gene ontology Molecular function calmodulin-dependent protein kinase activity transferase activity nucleotide binding inositol-1,4,5-trisphosphate 3-kinase activity ATP binding calmodulin binding kinase activity Cellular component cytosol dendritic spine Biological process dendritic spine maintenance protein phosphorylation inositol phosphate metabolic process positive regulation of dendritic spine morphogenesis actin cytoskeleton organization inositol metabolic process phosphorylation signal transduction regulation of synaptic plasticity inositol phosphate biosynthetic process Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3706 228550 Ensembl ENSG00000137825 ENSMUSG00000027296 UniProt P23677 Q8R071 RefSeq (mRNA) NM_002220 NM_146125 RefSeq (protein) NP_002211 NP_666237 Location (UCSC) Chr 15: 41.49 – 41.5 Mb Chr 2: 119.57 – 119.58 Mb PubMed search [3] [4]
Wikidata
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Structure

ITPKA is one of three inositol-trisphosphate 3-kinase (ITP3K) genes in humans. ITP3K proteins regulate inositol phosphate metabolism by phosphorylation of the second messenger inositol 1,4,5-trisphosphate to produce Ins(1,3,4,5)P4, which is sometimes abbreviated as IP4. Structurally, ITPKA belongs to the inositol polyphosphate kinase (IPK) family. The activity of the inositol 1,4,5-trisphosphate 3-kinase is responsible for regulating the levels of a large number of inositol polyphosphates that are important in cellular signaling, most notably, inositol trisphosphate, which is the enzyme's only substrate. Both calcium/calmodulin and protein phosphorylation mechanisms control its activity. It is also a substrate for the cyclic AMP-dependent protein kinase, calcium/calmodulin- dependent protein kinase II, and protein kinase C in vitro. ITPKA and ITPKB are 68% identical in the C-terminus region The amino- terminal region of ITPKA binds filamentous actin. This property localizes the ITPKA to dendritic spines in principal neurons.^[8][9][10] ITPKA is expressed physiologically in neurons, but it is sometimes expressed in cancer cells and may contribute to processes of metastasis.^[11]

Physiological function

ITPKA participates in learning and memory processes in neurons.^[12][13]

Roles in human disease

Although ITPKA is expressed physiologically in neurons and testis, it sometimes becomes expressed in cancer cells, and the expression usually makes the cancer more aggressive.^[11][14]

Relationship to F-tractin

F-tractin is amino acids 9-52 of rat ITPKA. It was later determined that amino acids 9-40 were sufficient for binding filamentous actin.^[15][16] When fused to a reporter, such as green fluorescent protein, It is useful for the visualization of actin dynamics in living cells.^[17][18]