• Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

Akt phosphorylates and regulates the orphan nuclear receptor Nur77.

The immediate early gene NUR77 (also called NGFI-B) is required for T cell antigen receptor-mediated cell death and is induced to very high levels in immature thymocytes and T cell hybridomas undergoing apoptosis. The Akt (PKB) kinase is a key player in transduction of anti-apoptotic and proliferative signals in T cells. Because Nur77 has a putative Akt phosphorylation site at Ser-350, and phosphorylation of this residue is critical for the transactivation activity of Nur77, we investigated whether Akt regulates Nur77. Coimmunoprecipitation experiments showed the detection of Nur77 in Akt immune complexes, suggesting that Nur77 and Akt physically interact. We further show that Akt specifically phosphorylates Ser-350 of the Nur77 protein within its DNA-binding domain in vitro and in vivo in 293 and NIH 3T3 cells. Because phosphorylation of Ser-350 of Nur77 is critical for its function as a transcription factor, we examined the effect of Akt on this function. By using luciferase assay experiments, we showed that phosphorylation of Nur77 by Akt decreased the transcriptional activity of Nur77 by 50--85%. Thus, we show that Akt interacts with Nur77 and inactivates Nur77 by phosphorylation at Ser-350 in a phosphatidylinositol 3-kinase-dependent manner, connecting the phosphatidylinositol 3-kinase-dependent Akt pathway and a nuclear receptor pathway.

Pubmed ID: 11274386

Authors

  • Pekarsky Y
  • Hallas C
  • Palamarchuk A
  • Koval A
  • Bullrich F
  • Hirata Y
  • Bichi R
  • Letofsky J
  • Croce CM

Journal

Proceedings of the National Academy of Sciences of the United States of America

Publication Data

March 27, 2001

Associated Grants

  • Agency: NCI NIH HHS, Id: CA81534

Mesh Terms

  • 3T3 Cells
  • Animals
  • Cells, Cultured
  • DNA-Binding Proteins
  • Humans
  • Mice
  • Nuclear Receptor Subfamily 4, Group A, Member 1
  • Phosphorylation
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-akt
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Steroid
  • Transcription Factors
  • Transcription, Genetic