Isolation of a src homology 2-containing tyrosine phosphatase

Proc Natl Acad Sci U S A. 1992 Feb 1;89(3):1123-7. doi: 10.1073/pnas.89.3.1123.


Tyrosine phosphorylation is controlled by the opposing actions of tyrosine kinases and phosphotyrosine phosphatases (PTPs). src homology 2 domains (SH2) are found in several types of signaling proteins, including some tyrosine kinases. These domains bind phosphotyrosyl proteins and thus help promote signal transduction. Using mixed oligonucleotide-directed polymerase chain reactions, two previously undescribed rat PTP cDNA fragments were generated. Through subsequent screening of rat megakaryocyte and human erythroleukemia libraries, we obtained a full-length coding sequence for one of these fragments. This cDNA, SH-PTP1, encodes a tyrosine phosphatase containing two highly conserved SH2 domains. SH-PTP1, with a 2.4-kilobase mRNA, a predicted open reading frame of 595 amino acids, and a structure suggesting a nontransmembrane protein, is expressed primarily in hematopoietic and epithelial cells. When expressed in Escherichia coli, SH-PTP1 possesses PTP activity. The structure of SH-PTP1 establishes an additional branch of the tyrosine phosphatase family and suggests mechanisms through which tyrosine phosphatases might participate in signal transduction pathways.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Blotting, Southern
  • Cloning, Molecular
  • Gene Expression
  • Genes
  • Humans
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • Protein Tyrosine Phosphatases / chemistry
  • Protein Tyrosine Phosphatases / genetics*
  • RNA, Messenger / genetics
  • Rats
  • Recombinant Proteins / metabolism
  • Sequence Alignment


  • RNA, Messenger
  • Recombinant Proteins
  • Protein Tyrosine Phosphatases

Associated data

  • GENBANK/M77273