lck is a member of the src family of tyrosine protein kinase genes expressed predominantly in T-lymphocytes. Its product, p56$ sp{ rm lck}$ is physically and functionally associated with the CD4 and CD8 T-cell surface antigens, suggesting a possible role in CD4/CD8-mediated tyrosine phosphorylation signals during the process of antigen stimulation. Activation of p56$ sp{ rm lck}$ by mutation of tyrosine 505 was prevented by further mutation of either the site of autophosphorylation, tyrosine 394 to phenylalanine, or the site of myristylation, glycine 2 to alanine, as determined by the effects of overexpression of these p56$ sp{ rm lck}$ mutants in rodent fibroblasts. The role of activation of p56$ sp{ rm lck}$ in T-cells was examined by overexpression of the tyrosine 505-to-phenylalanine mutant in a CD4-negative, MHC-class II restricted T-cell hybridoma. The enhancement of T-cell responsiveness observed with expression of activated Lck was qualitatively similar to the effect of expression of CD4 in these cells, providing evidence that p56$ sp{ rm lck}$ positively regulates T-cell functions and that it mediates some of the functions of CD4 and CD8 during antigen stimulation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.60504 |
| Date | January 1991 |
| Creators | Abraham, Ninan |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Division of Experimental Medicine.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001243463, proquestno: AAIMM72068, Theses scanned by UMI/ProQuest. |
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