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Protein interactions between CD2 and Lck are required for the lipid raft distribution of CD2.
Protein interactions between CD2 and Lck are required for the lipid raft distribution of CD2.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2008 Jan 15; Vol. 180 (2), pp. 988-97. - Publication Year :
- 2008
-
Abstract
- In T lymphocytes, lipid rafts are preferred sites for signal transduction initiation and amplification. Many cell membrane receptors, such as the TCR, coreceptors, and accessory molecules associate within these microdomains upon cell activation. However, it is still unclear in most cases whether these receptors interact with rafts through lipid-based amino acid modifications or whether raft insertion is driven by protein-protein interactions. In murine T cells, a significant fraction of CD2 associates with membrane lipid rafts. We have addressed the mechanisms that control the localization of rat CD2 at the plasma membrane, and its redistribution within lipid rafts induced upon activation. Following incubation of rat CD2-expressing cells with radioactive-labeled palmitic acid, or using CD2 mutants with Cys226 and Cys228 replaced by alanine residues, we found no evidence that rat CD2 was subjected to lipid modifications that could favor the translocation to lipid rafts, discarding palmitoylation as the principal mechanism for raft addressing. In contrast, using Jurkat cells expressing different CD2 and Lck mutants, we show that the association of CD2 with the rafts fully correlates with CD2 capacity to bind to Lck. As CD2 physically interacts with both Lck and Fyn, preferentially inside lipid rafts, and reflecting the increase of CD2 in lipid rafts following activation, CD2 can mediate the interaction between the two kinases and the consequent boost in kinase activity in lipid rafts.
- Subjects :
- Animals
CD2 Antigens analysis
CD2 Antigens genetics
Cell Line, Tumor
Cell Membrane chemistry
Cell Membrane immunology
Cysteine chemistry
Cysteine metabolism
Humans
Jurkat Cells
Membrane Microdomains chemistry
Membrane Microdomains enzymology
Mice
Palmitic Acid metabolism
Rats
Rats, Wistar
T-Lymphocytes enzymology
Thymoma
CD2 Antigens metabolism
Lymphocyte Specific Protein Tyrosine Kinase p56(lck) metabolism
Membrane Microdomains metabolism
T-Lymphocytes immunology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 180
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 18178839
- Full Text :
- https://doi.org/10.4049/jimmunol.180.2.988