The PI 3-kinases are ubiquitous, heterodimeric enzymes that play a pivotal role in the regulation of many cellular processes, including cell growth, motility, proliferation, and survival. Activated PI 3-kinase phosphorylates phosphoinositol (PI) substrates to produce PI(3)P, PIP₂, and  PIP₃, which act as second messengers and recruit the PI 3-K-dependent serine/threonine kinases (PDK1) and Akt from the cytoplasm to the plasma membrane.

Subsequent phosphorylation of Akt on Thr³⁰⁸ and Ser⁴⁷³ fully activates the enzyme. The action of PI 3-Kinase is attenuated by the action of two phosphatases, PTEN and SHIP. PTEN acts on the 3-position to convert PIP₃ back to PIP₂. On the other hand, the SHIP removes phosphate from the 5-position to produce PI(3,4)P₂. PTEN deficiency has been reported in several human cancers, which makes them less susceptible to apoptotic stimuli. Inhibiting PI 3-kinase presents an opportunity to block a major cancer cell survival signaling pathway and overcome the effects of PTEN deletion or deficiency. This would also enhance tumor sensitivity to a wide variety of chemotherapeutic agents. Calbiochem® introduces two new isozyme-specific PI-3 kinases and inhibitors to complement its already existing line of products for PI 3-K signaling pathway research.


NEW! PI 3-Kinases

Product Cat. No. PI 3-Kb, p110b/p85a, Human, Recombinant, S. frugiperda 526554 PI 3-Kd, p110d/p85a, GST-Fusion, Human, Recombinant, S. frugiperda 526558 PI 3-Kg, His•Tag®, Human, Recombinant, S. frugiperda 526556

PI 3-K Inhibitors

Product Cat. No. PI 3-Ka Inhibitor VIII 528116 PI 3-Kb Inhibitor VI, TGX-221 528113 PI 3-Kg/CKII Inhibitor 528112

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