Identification of a novel dimeric phosphoprotein (PP29/30) associated with signaling receptors in human T lymphocytes and natural killer cells.
Two-dimensional gel electrophoresis of in vitro phosphorylated proteins coprecipitated by CD2 monoclonal antibody (mAb) from Brij58 lysates of resting human T lymphocytes and natural killer (NK) cells resulted in the identification of a novel 29/30-kD disulfide-linked dimer (pp29/30). Comparative two-dimensional analysis of CD2, CD3, CD4, CD5, and CD8 immunoprecipitates revealed that pp29/30 associates with these signaling receptor complexes but not with CD18, CD27, and CD29 in human T lymphocytes. Analysis of CD2 immunoprecipitates prepared from T cell antigen receptor/CD3-modulated T lymphocytes indicated that pp29/30 preferentially associates and comodulates with the human T cell antigen receptor (TCR). Since tyrosine phosphorylated pp29/30 selectively interacts with the Src homology type 2 domains (SHZ) of the protein tyrosine kinases p56lck and p59fyn but not ZAP70 the present data suggest that pp29/30 represents a novel signaling receptor associated phosphoprotein likely involved in the activation of human T lymphocytes and NK cells.
Schraven
B
B
Department of Applied Immunology, Deutsches Krebsforschungszentrum, Heidelberg, Germany.
Ratnofsky
S
S
Gaumont
Y
Y
Lindegger
H
H
Kirchgessner
H
H
Bruyns
E
E
Moebius
U
U
Meuer
S C
SC
D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000276:immunology; D018801:CD2 Antigens; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry* / Q000502:physiology; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D008970:Molecular Weight; D010750:Phosphoproteins / Q000097:blood* / Q000276:immunology / Q000502:physiology; D010766:Phosphorylation; D011233:Precipitin Tests; D011518:Proto-Oncogene Proteins / Q000032:analysis; D051076:Proto-Oncogene Proteins c-fyn; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000502:physiology; D011971:Receptors, Immunologic / Q000032:analysis* / Q000276:immunology; D013601:T-Lymphocytes / Q000737:chemistry* / Q000502:physiology
D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D011971:Receptors, Immunologic; C494957:FYN protein, human; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn