Structural requirements for function of the Crkl adapter protein in fibroblasts and hematopoietic cells

Kristen Senechal, Conor Heaney, Brian Druker, Charles L. Sawyers

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

Crkl is an adapter protein and phosphotyrosine-containing substrate implicated in transformation by the bcr-abl oncogene and in signaling by cytokines. When phosphorylated, Crkl binds through its Src homology 2 (SH2) domain to other tyrosine phosphoproteins such as paxillin and Cbl. Overexpression of Crkl in fibroblasts induces transformation. Here we examine the role of Crkl in hematopoietic cells and find that overexpression of Crkl confers a signal leading to increased adhesion to fibronectin. In both fibroblasts and hematopoietic cells, individual mutations or deletions of each SH2 and SH3 domain abrogated transformation and adhesion, respectively, indicating that interactions with other proteins such as Cbl and paxillin (SH2 domain) and Abl, Sos, and C3G (N-terminal SH3 domain) are essential for biological activity. In vivo and in vitro tryptic phosphopeptide mapping studies show that Crkl is phosphorylated on multiple tyrosine residues when overexpressed or when activated by Bcr-Abl. Mutation at tyrosine 207, a residue conserved in c-Crk, abrogates all in vivo tyrosine phosphorylation of Crkl. Despite this loss of phosphotyrosine, mutation at this site enhanced Crkl function as measured by complex formation with SH2 binding proteins, signal transduction to Jun Kinase, and fibroblast transformation. These observations implicate Crkl in cellular adhesion and demonstrate that Y207 functions as a negative regulatory site.

Original languageEnglish (US)
Pages (from-to)5082-5090
Number of pages9
JournalMolecular and Cellular Biology
Volume18
Issue number9
StatePublished - 1998

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src Homology Domains
Fibroblasts
Tyrosine
Paxillin
Phosphotyrosine
Proteins
abl Genes
Phosphopeptides
Mutation
Sequence Deletion
Phosphoproteins
Fibronectins
Signal Transduction
Carrier Proteins
Phosphotransferases
Phosphorylation
Cytokines

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cell Biology

Cite this

Structural requirements for function of the Crkl adapter protein in fibroblasts and hematopoietic cells. / Senechal, Kristen; Heaney, Conor; Druker, Brian; Sawyers, Charles L.

In: Molecular and Cellular Biology, Vol. 18, No. 9, 1998, p. 5082-5090.

Research output: Contribution to journalArticle

Senechal, Kristen ; Heaney, Conor ; Druker, Brian ; Sawyers, Charles L. / Structural requirements for function of the Crkl adapter protein in fibroblasts and hematopoietic cells. In: Molecular and Cellular Biology. 1998 ; Vol. 18, No. 9. pp. 5082-5090.
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