Description
General description
Research area: Cell Signaling
PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit a) is one of the four subunits of the 110kDa catalytic subunit of PI3K protein, which contains a regulatory region of 85kDa. PI3K proteins form a family of lipid kinases. This gene is localized to human chromosome 3q.Three different classes of PI3Ks (I – III) have been discovered.
Application
PI3 kinase (p110a/p85a) Active human has been used for the study of enzyme kinetics, screening inhibitors, and selectivity profiling.
Biochem/physiol Actions
PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit a) is one of the four catalytic subunits of PI3K protein, which plays an essential role in extracellular growth signaling. It phosphorylates and activates protein kinase B (PKB) protein. This protein has a wide range of physiological functions, such as proliferation, cell cycle, survival, adhesion, motility, apoptosis, angiogenesis, DNA repair, senescence, and cellular metabolism, and plays a central role in multiple types of cancers. It also functions as an intermediary in cellular signaling and is primarily recognized for its involvement in the Phosphoinositide 3-kinase/ Protein kinase B/ mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway. PIK3CA gene is either mutated or amplified in brain, breast, stomach, liver, ovary, and colon cancers. Mutation in this gene leads to enhanced PI3K activity, and it is a candidate transforming oncogene. It is over-expressed in invasive breast cancer and is a marker for poor prognosis. This gene is amplified in high-grade dysplastic lesions from bronchial biopsy specimens obtained from preinvasive squamous lung cancer. Frequency of mutations in the PIK3CA gene is higher in tumors without lymph node metastasis than in those with gastric cancer. Thus, it might be essential to evaluate the mutations in this gene to determine cetuximab treatment in gastric cancer patients.
Physical form
Formulated in 25 mM Tris-HCl, pH 8.0, 100 mM NaCl, 0.05% Tween-20, 30% glycerol and 3 mM DTT.
Preparation Note
Thaw on ice. Upon first thaw, briefly spin tube containing enzyme to recover full content of the tube. Aliquot enzyme into single use aliquots. Store remaining undiluted enzyme in aliquots at -70°C. Note: Enzyme is very sensitive to freeze/thaw cycles.
Other Notes
One unit of 110a/p85a kinase activity is defined as the amount of enzyme required to produce 1 pmol of Phosphoinositol-3, 4,5-Trisphosphate/min at 37°C.
