Identification of a human Akt3 (protein kinase B gamma) which contains the regulatory serine phosphorylation site

Biochem Biophys Res Commun. 1999 Apr 21;257(3):906-10. doi: 10.1006/bbrc.1999.0559.


The family of protein kinases called Akt, protein kinase B (PKB), or related to A and C kinase (RAC) have been implicated in numerous biological processes including adipocyte and muscle differentiation, glycogen synthesis, glucose uptake, apoptosis and cellular proliferation. There are 3 known isoforms of this enzyme in mammalian cells (1/alpha, 2/beta and 3/gamma). Akt1 and 2 contain a key regulatory serine phosphorylation site in the carboxy-terminal region of the protein. However, the reported sequence of the rat Akt3 protein differed significantly from this in that it lacked 25 amino acids in the C-terminal region, including this key regulatory serine phosphorylation site (Biochem. Biophys. Res. Commun. 216, 526-534). In the present studies we show that the deduced sequence of human Akt3 contains this serine and that it is phosphorylated in response to insulin. These results indicate that human Akt3 is regulated similarly to Akt1 and Akt2.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Western
  • CHO Cells
  • Cloning, Molecular
  • Cricetinae
  • Expressed Sequence Tags
  • Gene Expression Regulation / drug effects
  • Humans
  • Insulin / pharmacology
  • Introns / genetics
  • Molecular Sequence Data
  • Oncogene Proteins / chemistry
  • Oncogene Proteins / genetics
  • Oncogene Proteins / metabolism*
  • Phosphorylation / drug effects
  • Phosphoserine / metabolism*
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Sequence Homology, Amino Acid
  • Transfection
  • Tumor Cells, Cultured


  • Insulin
  • Oncogene Proteins
  • RNA, Messenger
  • Phosphoserine
  • AKT3 protein, human
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt

Associated data

  • GENBANK/AF135794