In vitro activation of Stat3 by epidermal growth factor receptor kinase

Ohkmae Kim, Timothy S. Schaefer, Daniel Nathans

Research output: Contribution to journalArticle

156 Citations (Scopus)

Abstract

Stat proteins are SH2 domain-containing transcription factors that are activated in cells by various cytokines and growth factors. In the case of cytokines whose receptors lack protein kinase activity, phosphorylation- activation is mediated by members of the JAK family of tyrosine protein kinases. In the case of growth factors whose receptors have intrinsic tyrosine protein kinase activity, it is thought that Stat proteins can be activated either directly by the receptor or indirectly through JAK proteins. To test the possibility of direct activation, we have used purified Stat3α, Stat3β, and epidermal growth factor receptor kinase produced in recombinant baculovirus-infected Sf9 insect cells. The Stat proteins formed a stable complex with the receptor kinase, and they were phosphorylated on tyrosine by the receptor kinase and activated for binding to DNA, properties shared with Stat proteins purified from Sf9 cells coexpressing JAK1 or JAK2. Both JAK-phosphorylated Stat3β and Stat3β phosphorylated in vitro by the receptor kinase were 20-50 times more active on a molar basis for DNA binding than phosphorylated Stat3α. We conclude that Stat3 isoforms can be directly phosphorylated and thereby activated in vitro by the epidermal growth factor receptor kinase.

Original languageEnglish
Pages (from-to)13704-13708
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume93
Issue number24
DOIs
Publication statusPublished - 1996 Nov 26
Externally publishedYes

Fingerprint

Epidermal Growth Factor Receptor
Sf9 Cells
Protein-Tyrosine Kinases
Proteins
Phosphotransferases
Cytokine Receptors
src Homology Domains
Growth Factor Receptors
Baculoviridae
DNA
Receptor Protein-Tyrosine Kinases
Protein Kinases
Insects
Intercellular Signaling Peptides and Proteins
Protein Isoforms
Transcription Factors
Phosphorylation
Cytokines
In Vitro Techniques

Keywords

  • cytokines
  • growth factors
  • JAK proteins
  • signal transduction

ASJC Scopus subject areas

  • General
  • Genetics

Cite this

In vitro activation of Stat3 by epidermal growth factor receptor kinase. / Kim, Ohkmae; Schaefer, Timothy S.; Nathans, Daniel.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 93, No. 24, 26.11.1996, p. 13704-13708.

Research output: Contribution to journalArticle

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AU - Nathans, Daniel

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