These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Phosphorylation occurs in the amino terminus of the Raf-1 protein.
    Author: McGrew BR, Nichols DW, Stanton VP, Cai H, Whorf RC, Patel V, Cooper GM, Laudano AP.
    Journal: Oncogene; 1992 Jan; 7(1):33-42. PubMed ID: 1741164.
    Abstract:
    The ability of the Raf-1 protein to morphologically transform murine fibroblasts can be activated by amino-terminal deletions or substitutions. We have compared the phosphorylation states of full-length and representative transforming and non-transforming amino-terminal deletion mutants of the Raf-1 protein using phosphoamino acid analysis and tryptic phosphopeptide mapping. Several [32P]orthophosphate-labeled tryptic phosphopeptides that were present in the full-length Raf-1 protein were absent from the highly transforming 22W Raf-1 mutant (lacking 305 amino-terminal residues). Peptide-specific antisera localized Raf-1 phosphorylation sites to several amino-terminal cyanogen bromide and tryptic peptides that are deleted from the 22W protein. A major phosphorylated tryptic peptide of the Raf-1 protein was immunoprecipitated by antiserum directed against amino acid residues 257-275, a highly conserved region of the raf family. This tryptic peptide is entirely deleted from the highly transforming 22W protein. Subtractive Edman degradation and electrophoretic analysis of the immunoprecipitated tryptic peptide indicated that phosphorylation of the Raf-1 protein occurs at serine 259. Multiple phosphorylated tryptic peptide forms were immunoprecipitated by antiserum directed against Raf-1 residues 283-309. The majority of this tryptic peptide is also deleted from the highly transforming Raf-1 mutant 22W.
    [Abstract] [Full Text] [Related] [New Search]