T cell CD3-zeta eta heterodimer expression and coupling to phosphoinositide hydrolysis.
The T cell antigen receptor consists of an antigen-binding heterodimer that is noncovalently associated with at least five CD3 subunits (gamma, delta, epsilon, zeta, and eta). The CD3-zeta chains are either disulfide-linked homodimers (CD3-zeta 2) or disulfide-linked heterodimers with eta (CD3-zeta eta). Variants of a murine antigen-specific T cell hybridoma that express normal amounts of CD3-zeta 2 but decreased amounts of CD3-zeta eta were isolated. When activated, the parental cell line increased both phosphatidylinositol hydrolysis and serine-specific protein kinase activity to a much greater extent than the variants. In contrast, the activation of a tyrosine-specific kinase after stimulation with a cross-linking antibody to CD3 was similar among these cells. There was a positive linear relation between the expression of CD3-zeta eta and phosphoinositide hydrolysis stimulated by the TCR, suggesting a differential coupling of the T cell alpha beta heterodimer to signal transduction mechanisms due to alpha beta association with either CD3-zeta 2 or CD3-zeta eta.
Merćep
M
M
Biological Response Modifiers Program, National Cancer Institute, Bethesda, MD 20892.
Bonifacino
J S
JS
Garcia-Morales
P
P
Samelson
L E
LE
Klausner
R D
RD
Ashwell
J D
JD
D000818:Animals; D000941:Antigens / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D017252:CD3 Complex; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D046911:Macromolecular Substances; D008565:Membrane Proteins; D051379:Mice; D010716:Phosphatidylinositols / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011493:Protein Kinase C / Q000502:physiology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*
D000941:Antigens; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D046911:Macromolecular Substances; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; C054979:antigen T cell receptor, zeta chain; D011493:Protein Kinase C