Class IA phosphoinositide 3-kinases are obligate p85-p110 heterodimers.

@article{Geering2007ClassIP,
  title={Class IA phosphoinositide 3-kinases are obligate p85-p110 heterodimers.},
  author={Barbara Geering and Pedro R Cutillas and Gemma E. Nock and Severine I. Gharbi and Bart Vanhaesebroeck},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={2007},
  volume={104 19},
  pages={7809-14}
}
Class IA phosphoinositide 3-kinases (PI3Ks) signal downstream of tyrosine kinases and Ras and control a wide variety of biological responses. In mammals, these heterodimeric PI3Ks consist of a p110 catalytic subunit (p110alpha, p110beta, or p110delta) bound to any of five distinct regulatory subunits (p85alpha, p85beta, p55gamma, p55alpha, and p50alpha, collectively referred to as "p85s"). The relative expression levels of p85 and p110 have been invoked to explain key features of PI3K signaling… CONTINUE READING