The Cytoplasmic Region of the Erythropoietin Receptor Contains Nonoverlapping Positive and Negative Growth-Regulatory Domains

Alan D. D'Andrea, Akihiko Yoshimura, Hagop Youssoufian, Leonard I. Zon, Jah Won Koo, Harvey F. Lodishi

Research output: Contribution to journalArticle

210 Citations (Scopus)

Abstract

The erythropoietin (EPO) receptor (EPO-R), a member of a large cytokine receptor superfamily, has a 236-amino-acid cytoplasmic region which contains no obvious tyrosine kinase or other catalytic domain. In order to delineate the linear functional domains of the cytoplasmic tail, we generated truncated mutant cDNAs which were transfected into a murine interleukin-3-dependent cell line, Ba/F3, and the EPO-dependent growth characteristics of the stable transfectants were assayed. We identified two unique domains of the cytoplasmic tail. A membrane-proximal positive signal transduction domain of ≤103 amino acids, in a region highly similar to the interleukin-2 receptor β chain, was sufficient for EPO-mediated signal transduction. A carboxy-terminal negative-control domain, a serine-rich region of approximately 40 amino acids, increased the EPO requirement for the Ba/F3 transfectants without altering EPO-R cell surface expression, affinity for EPO, receptor oligosaccharide processing, or receptor endocytosis. Truncation of this negative-control domain allowed the Ba/F3 transfectants to grow maximally in only 1 pM EPO, 1/10 the concentration required for growth of cells expressing the wild-type EPO-R. All truncated EPO-R mutants which retained the transmembrane region of the EPO-R polypeptide bound to the gp55 envelope protein of Friend spleen focus-forming virus. Only the functional EPO-R mutants were activated by the gp55, however, suggesting that gp55- and EPO-mediated signaling occur via a similar mechanism.

Original languageEnglish
Pages (from-to)1980-1987
Number of pages8
JournalMolecular and Cellular Biology
Volume11
Issue number4
DOIs
Publication statusPublished - 1991 Apr
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'The Cytoplasmic Region of the Erythropoietin Receptor Contains Nonoverlapping Positive and Negative Growth-Regulatory Domains'. Together they form a unique fingerprint.

  • Cite this