Concanavalin A induces a cytoskeletal association of T200 molecules in T lymphocytes.
A recent report indicated that T200 molecules interact with elements of the cytoskeleton in BW5147 T lymphoma cells. We have confirmed the cytoskeletal association of T200 by examining nonionic detergent-soluble and detergent-insoluble fractions of murine T cell tumor cell lines, cloned cytotoxic T lymphocyte lines, and thymocytes. Concanavalin A (Con A)-treated and untreated cells were extracted with 0.5% Triton X-100 and the remaining insoluble material was extracted under conditions allowing actin depolymerization. In the absence of Con A treatment, little T200 could be recovered from the depolymerized insoluble fraction. However, in T cells treated with capping concentrations of Con A, a considerable amount of T200 was rendered insoluble in nonionic detergent, and T200 could be recovered from the insoluble fraction by a buffer which dissociates actin polymers. A lesser, but still significant, amount of T200 associated with the detergent-insoluble fraction of thymocytes treated with concentrations of Con A and succinyl Con A, which are mitogenic for T cells. We also found that in T cells treated with mitogenic concentrations of succinyl Con A, more T200 associated with cytoskeleton than did H-2 or LFA-1 molecules. Because T200 is such a predominant molecule on the surface of T cells, such translocations of the molecule may have a major impact on the physiology of the cell, especially if T200 functions as a protein tyrosine phosphatase as recent evidence by others suggests.
Taffs
R E
RE
Department of Microbiology, Montana State University, Bozeman 59717.
Ewald
S J
SJ
D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism*; D003208:Concanavalin A / Q000494:pharmacology*; D003599:Cytoskeleton / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006649:Histocompatibility Antigens / Q000378:metabolism*; D017493:Leukocyte Common Antigens; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D011233:Precipitin Tests; D013601:T-Lymphocytes / Q000276:immunology* / Q000648:ultrastructure; D013696:Temperature; D014407:Tumor Cells, Cultured / Q000276:immunology
D000943:Antigens, Differentiation; D006649:Histocompatibility Antigens; D008565:Membrane Proteins; D003208:Concanavalin A; D017493:Leukocyte Common Antigens