Description: Homo sapiens phosphatidylinositol-5-phosphate 4-kinase, type II, alpha (PIP4K2A), mRNA. RefSeq Summary (NM_005028): Phosphatidylinositol-5,4-bisphosphate, the precursor to second messengers of the phosphoinositide signal transduction pathways, is thought to be involved in the regulation of secretion, cell proliferation, differentiation, and motility. The protein encoded by this gene is one of a family of enzymes capable of catalyzing the phosphorylation of phosphatidylinositol-5-phosphate on the fourth hydroxyl of the myo-inositol ring to form phosphatidylinositol-5,4-bisphosphate. The amino acid sequence of this enzyme does not show homology to other kinases, but the recombinant protein does exhibit kinase activity. This gene is a member of the phosphatidylinositol-5-phosphate 4-kinase family. [provided by RefSeq, Jul 2008]. Transcript (Including UTRs) Position: hg19 chr10:22,823,766-23,003,503 Size: 179,738 Total Exon Count: 10 Strand: - Coding Region Position: hg19 chr10:22,826,130-23,003,255 Size: 177,126 Coding Exon Count: 10
ID:PI42A_HUMAN DESCRIPTION: RecName: Full=Phosphatidylinositol 5-phosphate 4-kinase type-2 alpha; EC=2.7.1.149; AltName: Full=1-phosphatidylinositol 5-phosphate 4-kinase 2-alpha; AltName: Full=Diphosphoinositide kinase 2-alpha; AltName: Full=PIP5KIII; AltName: Full=Phosphatidylinositol 5-phosphate 4-kinase type II alpha; Short=PI(5)P 4-kinase type II alpha; Short=PIP4KII-alpha; AltName: Full=PtdIns(4)P-5-kinase B isoform; AltName: Full=PtdIns(4)P-5-kinase C isoform; AltName: Full=PtdIns(5)P-4-kinase isoform 2-alpha; FUNCTION: Catalyzes the phosphorylation of phosphatidylinositol 5- phosphate (PtdIns5P) on the fourth hydroxyl of the myo-inositol ring, to form phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). May exert its function by regulating the levels of PtdIns5P, which functions in the cytosol by increasing AKT activity and in the nucleus signals through ING2. May regulate the pool of cytosolic PtdIns5P in response to the activation of tyrosine phosphorylation. May negatively regulate insulin- stimulated glucose uptake by lowering the levels of PtdIns5P. May be involved in thrombopoiesis, and the terminal maturation of megakaryocytes and regulation of their size. CATALYTIC ACTIVITY: ATP + 1-phosphatidyl-1D-myo-inositol 5- phosphate = ADP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate. BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=50 uM for phosphatidylinositol-5- phosphate; Vmax=466 pmol/min/ug enzyme; SUBUNIT: Homodimer (By similarity). Interacts with PIP4K2B. Interaction with PIP4K2B may regulate localization to the nucleus. SUBCELLULAR LOCATION: Cell membrane (By similarity). Nucleus. Cytoplasm. Note=May translocate from the cytosol to the cell membrane upon activation of tyrosine phosphorylation. May translocate from the inner to the outer segments of the rod photoreceptor cells in response to light (By similarity). Localization to the nucleus is modulated by the interaction with PIP4K2B. TISSUE SPECIFICITY: Expressed ubiquitously, with high levels in the brain. Present in most tissues, except notably skeletal muscle and small intestine. SIMILARITY: Contains 1 PIPK domain. CAUTION: This protein was previously thought to be a phosphatidylinositol 4-phosphate 5-kinase.
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Genetic Association Studies of Complex Diseases and Disorders
Genetic Association Database (archive): PIP4K2A CDC HuGE Published Literature: PIP4K2A Positive Disease Associations: Prostatic Neoplasms
, Stroke Related Studies:
Prostatic Neoplasms Joanne M Murabito et al. BMC medical genetics 2007, A genome-wide association study of breast and prostate cancer in the NHLBI's Framingham Heart Study., BMC medical genetics.
[PubMed 17903305]
Although no association attained genome-wide significance, several interesting associations emerged for breast and prostate cancer. These findings can serve as a resource for replication in other populations to identify novel biologic pathways contributing to cancer susceptibility.
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on P48426
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.