Phospho-PI3KP85α/P55γ/P85β-Y467/Y199/Y464 Recombinant Rabbit mAb

Phospho-PI3KP85α/P55γ/P85β-Y467/Y199/Y464 refers to the phosphorylation status of key tyrosine residues on three different regulatory subunits of class I phosphatidylinositol 3-kinase (PI3K), specifically the Y467 site on the p85α subunit, the Y199 site on the p55γ subunit (which corresponds in sequence position), and the Y464 site on the p85β subunit. PI3K typically functions as a heterodimer composed of a regulatory subunit (such as p85α, p85β, or p55γ) and a catalytic subunit (such as p110), playing a central role in signaling pathways governing cell growth, survival, and metabolism. Phosphorylation at these specific sites serves as a critical molecular switch for PI3K signaling activation, typically occurring upon stimulation by growth factors and other extracellular cues, catalyzed by upstream tyrosine kinases, and is essential for recruiting the catalytic subunit to the plasma membrane and activating its lipid kinase function. Notably, recent studies have revealed that the significance of this phosphorylation extends far beyond classical signal activation: for example, phosphorylation of p85β at Y464 (mediated by focal adhesion kinase FAK) can drive its translocation from the cytoplasm to the nucleus, exerting an oncogenic function in clear cell renal cell carcinoma by suppressing the expression of the tumor suppressor gene RB1, suggesting that this phosphorylation may participate in non-classical nuclear regulatory mechanisms. The phosphorylation of these specific tyrosine residues on distinct subunits collectively constitutes the molecular basis for the precise regulation of the PI3K signaling network.