Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1992 Jun 25;267(18):12991-7.

Protein phosphatase inhibitors induce the sustained expression of the Egr-1 gene and the hyperphosphorylation of its gene product

X Cao  1 , R Mahendran, G R Guy, Y H Tan
Affiliations
  • PMID: 1320009
Free article

Protein phosphatase inhibitors induce the sustained expression of the Egr-1 gene and the hyperphosphorylation of its gene product

X Cao et al. J Biol Chem. .
Free article

Abstract

The immediate-early gene Egr-1 is strongly and rapidly induced in human and mouse Balb/c fibroblasts by okadaic acid and calyculin A, both specific inhibitors of protein serine/threonine phosphatases 1 and 2A. In contrast to the transient induction of the Egr-1 gene by serum or phorbol 12-myristate 13-acetate, these phosphatase inhibitors stimulated a sustained induction of the Egr-1 gene. The induction is shown to occur transcriptionally and is sustained post-transcriptionally. Okadaic acid-induced Egr-1 mRNA is significantly more stable than serum-induced Egr-1 mRNA. The half-life of serum-induced Egr-1 mRNA is estimated to be 12 min, compared with a half life of 2 h for okadaic acid-induced Egr-1 mRNA. Okadaic acid also induced the expression of the related immediate-early genes Egr-2 and Egr-3 albeit to a lesser extent than Egr-1. Treatment of cells with okadaic acid and calyculin A also induced the synthesis of Egr-1 protein. The Egr-1 protein is weakly or not phosphorylated in quiescent cells, but multiple species of the phosphorylated forms of the Egr-1 protein are detected in cells treated with either of the phosphatase inhibitors. Simultaneous treatment of cells with TPA and okadaic acid synergistically induced Egr-1 gene expression, and H7 strongly inhibits this induction. Taken together, the results indicate that the induction of Egr-1 gene transcription and the phosphorylation of the induced Egr-1 protein are under the control of protein kinase(s) and protein phosphatase(s). The phosphorylation and dephosphorylation of Egr-1 protein may play a role in controlling cell growth.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

MeSH terms

LinkOut - more resources

  NODES
twitter 2