SKAP-HOM, a novel adaptor protein homologous to the FYN-associated protein SKAP55

FEBS Lett. 1998 Sep 11;435(1):55-60. doi: 10.1016/s0014-5793(98)01040-0.


A recombinant GST-Fyn-SH2 domain was used to purify proteins from lysates of pervanadate treated EL4 cells. N-terminal sequencing and molecular cloning of one of the purified polypeptides resulted in the identification of a novel adaptor protein that shares strong structural homology to the recently cloned Fyn-associated adaptor protein SKAP55. This protein was termed SKAP-HOM (SKAP55 homologue). Despite their striking homology, SKAP55 and SKAP-HOM have distinct characteristics. Thus, unlike SKAP55, which is exclusively expressed in T lymphocytes, SKAP-HOM expression is ubiquitous. Furthermore, while SKAP55 is constitutively tyrosine phosphorylated in resting human T cells, SKAP-HOM is expressed as a non-phosphorylated protein in the absence of external stimulus but becomes phosphorylated following T cell activation. In addition, SKAP-HOM does not associate with p59fyn in T cells although it represents a specific substrate for the kinase in COS cells. Finally, we demonstrate that, as previously shown for SKAP55, SKAP-HOM interacts with the recently identified polypeptide SLAP-130.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Humans
  • Mice
  • Molecular Sequence Data
  • Phosphoproteins / biosynthesis
  • Phosphoproteins / chemistry*
  • Phosphoproteins / metabolism
  • Phosphorylation
  • Sequence Homology, Amino Acid*
  • Substrate Specificity
  • T-Lymphocytes / enzymology
  • Tumor Cells, Cultured
  • Tyrosine / metabolism
  • src-Family Kinases / metabolism


  • Phosphoproteins
  • SKAP1 protein, human
  • Tyrosine
  • src-Family Kinases

Associated data

  • GENBANK/AJ004886