Identification of four novel human phosphoinositide 3-kinases defines a multi-isoform subfamily

Biochem Biophys Res Commun. 1997 Jun 9;235(1):130-7. doi: 10.1006/bbrc.1997.6747.


Phosphoinositide (PI) 3-kinases have critical roles in diverse cellular signalling processes and in protein trafficking. This suggests that like other intracellular signalling molecules, e.g., phospholipase C and protein kinase C, there might be a large family of PI 3-kinase isoforms with the individual members having discrete signalling roles. Reverse transcription-polymerase chain reaction methods, using degenerate oligonucleotide primers against the lipid kinase consensus region, revealed eight sequences from human cDNA containing a high degree of identity to the family of PI 3-kinases. The sequences obtained included the previously described p110 alpha, p110 beta, and p110 gamma isoforms and HsVps34. Additionally, we have identified four novel sequences which are related to PI 3-kinases. Three of the novel sequences would appear to form a distinct sub-family of PI 3-kinases. We report the expression of these novel PI 3-kinases in human tissues and in cells derived from normal breast.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Northern
  • Breast / enzymology*
  • Cloning, Molecular
  • DNA Primers
  • Databases, Factual
  • Gene Expression
  • Humans
  • Isoenzymes / chemistry*
  • Isoenzymes / genetics
  • Lymph Nodes / enzymology
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor) / chemistry*
  • Phosphotransferases (Alcohol Group Acceptor) / genetics*
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism
  • Sequence Alignment
  • Tumor Cells, Cultured


  • DNA Primers
  • Isoenzymes
  • RNA, Messenger
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor)