The T-cell antigen CD5 acts as a receptor and substrate for the protein-tyrosine kinase p56lck. Export

@article{citeulike:562092, abstract = {CD5 is a T-cell-specific antigen which binds to the B-cell antigen CD72 and acts as a coreceptor in the stimulation of T-cell growth. CD5 associates with the T-cell receptor zeta chain (TcR zeta)/CD3 complex and is rapidly phosphosphorylated on tyrosine residues as a result of TcR zeta/CD3 ligation. However, despite this, the mechanism by which CD5 generates intracellular signals is unclear. In this study, we demonstrate that CD5 is coupled to the protein-tyrosine kinase p56lck and can act as a substrate for p56lck. Coexpression of CD5 with p56lck in the baculovirus expression system resulted in the phosphorylation of CD5 on tyrosine residues. Further, anti-CD5 and anti-p56lck coprecipitated each other in a variety of detergents, including Nonidet P-40 and Triton X-100. Anti-CD5 also precipitated the kinase from various T cells irrespective of the expression of TcR zeta/CD3 or CD4. No binding between p59fyn(T) and CD5 was detected in T cells. The binding of p56lck to CD5 induced a 10- to 15-fold increase in p56lck catalytic activity, as measured by in vitro kinase analysis. In vivo labelling with 32P(i) also showed a four- to fivefold increase in Y-394 occupancy in p56lck when associated with CD5. The use of glutathione S-transferase-Lck fusion proteins in precipitation analysis showed that the SH2 domain of p56lck could recognize CD5 as expressed in the baculovirus expression system. CD5 interaction with p56lck represents a novel variant of a receptor-kinase complex in which receptor can also serve as substrate. The CD5-p56lck interaction is likely to play roles in T-cell signalling and T-B collaboration.}, address = {Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115.}, author = {Raab, M. and Yamamoto, M. and Rudd, C. E.}, citeulike-article-id = {562092}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/7513045}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=7513045}, issn = {0270-7306}, journal = {Mol Cell Biol}, keywords = {cd3, cd5, fyn, lck, tyrosine}, month = {May}, number = {5}, pages = {2862--2870}, posted-at = {2006-03-24 09:10:29}, priority = {0}, title = {The T-cell antigen CD5 acts as a receptor and substrate for the protein-tyrosine kinase p56lck.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/7513045}, volume = {14}, year = {1994} }

TY - JOUR ID - citeulike:562092 L3 - citeulike-article-id:562092 N2 - CD5 is a T-cell-specific antigen which binds to the B-cell antigen CD72 and acts as a coreceptor in the stimulation of T-cell growth. CD5 associates with the T-cell receptor zeta chain (TcR zeta)/CD3 complex and is rapidly phosphosphorylated on tyrosine residues as a result of TcR zeta/CD3 ligation. However, despite this, the mechanism by which CD5 generates intracellular signals is unclear. In this study, we demonstrate that CD5 is coupled to the protein-tyrosine kinase p56lck and can act as a substrate for p56lck. Coexpression of CD5 with p56lck in the baculovirus expression system resulted in the phosphorylation of CD5 on tyrosine residues. Further, anti-CD5 and anti-p56lck coprecipitated each other in a variety of detergents, including Nonidet P-40 and Triton X-100. Anti-CD5 also precipitated the kinase from various T cells irrespective of the expression of TcR zeta/CD3 or CD4. No binding between p59fyn(T) and CD5 was detected in T cells. The binding of p56lck to CD5 induced a 10- to 15-fold increase in p56lck catalytic activity, as measured by in vitro kinase analysis. In vivo labelling with 32P(i) also showed a four- to fivefold increase in Y-394 occupancy in p56lck when associated with CD5. The use of glutathione S-transferase-Lck fusion proteins in precipitation analysis showed that the SH2 domain of p56lck could recognize CD5 as expressed in the baculovirus expression system. CD5 interaction with p56lck represents a novel variant of a receptor-kinase complex in which receptor can also serve as substrate. The CD5-p56lck interaction is likely to play roles in T-cell signalling and T-B collaboration. IS - 5 JF - Mol Cell Biol SN - 0270-7306 AD - Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115. EP - 2870 TI - The T-cell antigen CD5 acts as a receptor and substrate for the protein-tyrosine kinase p56lck. VL - 14 SP - 2862 KW - cd3 KW - cd5 KW - fyn KW - lck KW - tyrosine AU - Raab, M AU - Yamamoto, M AU - Rudd, CE PY - 1994/05// UR - http://view.ncbi.nlm.nih.gov/pubmed/7513045 ER -