Molecular interaction between the Fyn-associated protein SKAP55 and the SLP-76-associated phosphoprotein SLAP-130.
It has previously been reported that in resting T-lymphocytes the protein tyrosine kinase p59 constitutively co-precipitates with four phosphoproteins of 43, 55, 85, and 120 kDa, respectively. We have recently cloned the 55-kDa protein that was termed Src kinase-associated phosphoprotein of 55 kDa (SKAP55). Here we demonstrate that the recently characterized SH2-domain-containing leukocyte protein 76-associated phosphoprotein of 130 kDa (SLAP-130) is one of the components of the Fyn complex and that it also co-precipitates with SKAP55 in human T-cells. We establish that SKAP55 and SLAP-130 associate with each other when both molecules are co-expressed in COS cells. By co-transfection of truncated mutants of SKAP55 and SLAP-130 as well as by using the two-hybrid selection system, we further demonstrate that the association between SLAP-130 and SKAP55 is direct and involves the Src homology 3 domain of SKAP55 and the proline-rich sequence of SLAP-130.
Pubmed ID: 9748251 RIS Download
Adaptor Proteins, Signal Transducing | Animals | COS Cells | Carrier Proteins | Cloning, Molecular | Humans | Jurkat Cells | Mutation | Oligopeptides | Peptides | Phosphoproteins | Proto-Oncogene Proteins | Proto-Oncogene Proteins c-fyn | Signal Transduction | Transfection | src Homology Domains