P13K 1-phosphatidylinositol 3-kinase definition and studies

P13K 1-phosphatidylinositol 3-kinase definition

<enzyme>

<cell biology> An enzyme that catalyses the conversion of phosphatidylinositol to phosphatidylinositol 3-phosphate. This is the first committed step in the biosynthesis of phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate. This pathway is thought to play a critical role in DNA repair, v(d)j recombination and cell cyle checkpoints.37.

Chemical name: ATP:1-phosphatidyl-1D-myo-inositol 3-phosphotransferase

Registry number: EC 2.7.1.137

Online Medical Dictionary

Additional studies on its role:

Effects of Tyroserleutide on Gene Expression of Calmodulin and P13K in Hepatocellular Carcinoma

Oncogenic P13K Deregulates Transcription and Translation

A role for phosphoinositol-3-kinase (P13K) in the stimulation of hepatic taurocholate uptake by cyclic AMP

Laminin-332 promotes the invasion of oesophageal squamous cell carcinoma via P13K activation

Patent application title: THIAZOLOPYRIMIDINE P13K INHIBITOR COMPOUNDS AND METHODS OF USE

Expression Status and Mutational Analysis of the PTEN and P13K Subunit Genes in Ovarian Granulosa Cell Tumors

High D-glucose alters PI3K and Akt signaling and leads to endothelial cell migration,

proliferation and angiogenesis dysfunction

Organ-specific lymphangiectasia, arrested lymphatic sprouting, and maturation defects P13K gene

Organ-specific lymphangiectasia, arrested lymphatic sprouting, and maturation defects resulting from gene-targeting of the PI3K regulatory isoforms p85, p55, and p50

Dev Dyn. 2009 Oct

Mouta-Bellum C, Kirov A, Miceli-Libby L, Mancini ML, Petrova TV, Liaw L, Prudovsky I,Thorpe PE, Miura N, Cantley LC, Alitalo K, Fruman DA, Vary CP.

Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA.

email: Calvin P.H. Vary (varyc@mmc.org)

The phosphoinositide 3-kinase (PI3K) family has multiple vascular functions, but the specific regulatory isoform supporting lymphangiogenesis remains unidentified. Here, we report that deletion of the Pik3r1 gene, encoding the regulatory subunits p85alpha, p55alpha, and p50alpha impairs lymphatic sprouting and maturation, and causes abnormal lymphatic morphology, without major impact on blood vessels. Pik3r1 deletion had the most severe consequences among gut and diaphragm lymphatics, which share the retroperitoneal anlage, initially suggesting that the Pik3r1 role in this vasculature is anlage-dependent. However, whereas lymphatic sprouting toward the diaphragm was arrested, lymphatics invaded the gut, where remodeling and valve formation were impaired. Thus, cell-origin fails to explain the phenotype. Only the gut showed lymphangiectasia, lymphatic up-regulation of the transforming growth factor-beta co-receptor endoglin, and reduced levels of mature vascular endothelial growth factor-C protein. Our data suggest that Pik3r1 isoforms are required for distinct steps of embryonic lymphangiogenesis in different organ microenvironments, whereas they are largely dispensable for hemangiogenesis.

Wiley InterScience