Function of a heterologous muscarinic receptor in T cell antigen receptor signal transduction mutants.
Previously we have described a system of somatic cell genetics (J.CaM1 and J.CaM2) for analyzing signal transduction via the T cell antigen receptor complex (CD3/Ti). Here we describe a third mutant, J.CaM3, which also expresses high levels of receptors that are functionally impaired. Like J.CaM1, J.CaM3 demonstrates partial signal transduction via CD3/Ti to only certain stimuli. J.CaM1, J.CaM2, and J.CaM3 define three non-Ti complementation groups involved in receptor function. To evaluate the mutations further we have introduced a heterologous receptor, the human muscarinic receptor 1 (HM1), into the parental Jurkat and mutant cell lines. This receptor demonstrates signal transduction competence in all these hosts, indicating that 1) T cells express the necessary apparatus for the coupling of HM1 to second messenger generation and 2) the mutations in the J.CaM family all affect molecules that are specific to CD3/Ti, and not HM1, function. Finally, the HM1 receptor exhibits partial sensitivity to cholera toxin in Jurkat cells, in contrast to the virtually complete sensitivity of CD3/Ti to cholera toxin.
Goldsmith
M A
MA
Department of Medicine, School of Medicine, University of California, San Francisco.
Desai
D M
DM
Schultz
T
T
Weiss
A
A
D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000235:genetics / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000502:physiology; D017252:CD3 Complex; D002772:Cholera Toxin / Q000494:pharmacology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007163:Immunosorbent Techniques; D007295:Inositol Phosphates / Q000378:metabolism; D007525:Isoelectric Focusing; D015458:Leukemia, T-Cell; D009154:Mutation; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000502:physiology; D011976:Receptors, Muscarinic / Q000235:genetics / Q000502:physiology*; D015290:Second Messenger Systems / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics*; D014162:Transfection; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D007295:Inositol Phosphates; D011948:Receptors, Antigen, T-Cell; D011976:Receptors, Muscarinic; D002772:Cholera Toxin