Physical and functional association of the high affinity immunoglobulin G receptor (Fc gamma RI) with the kinases Hck and Lyn.
The high affinity immunoglobulin G (IgG) receptor Fc gamma RI (CD64) is expressed constitutively on monocytes and macrophages, and is inducible on neutrophils. Fc gamma RI has recently been shown to be associated with the signal transducing gamma subunit of the high-affinity IgE receptor (Fc epsilon RI gamma). Induction of cytoplasmic protein tyrosine phosphorylation by Fc gamma RI cross-linking is known to be important in mediating Fc gamma RI-coupled effector functions. Recently, syk has been implicated in this role. We now report that the src-type kinases hck and lyn are physically and functionally associated with Fc gamma RI. Hck and lyn coimmunoprecipitated with Fc gamma RI from detergent lysates of normal human monocytes and of the monocytic line THP-1. Hck and lyn showed rapidly increased phosphorylation and increased exogenous substrate kinase activity after cross-linking of Fc gamma RI. These results demonstrate both physical and functional association of the Fc gamma RI/Fc epsilon RI gamma receptor complex with hck and lyn, and suggest a potential signal transducing role for these kinases in monocyte/macrophage activation.
Wang
A V
AV
Division of Immunology, Children's Hospital, Boston, Massachusetts.
Scholl
P R
PR
Geha
R S
RS
D000595:Amino Acid Sequence; D006801:Humans; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000032:analysis* / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000502:physiology; D051572:Proto-Oncogene Proteins c-hck; D017452:Receptors, IgG / Q000032:analysis* / Q000502:physiology; D014407:Tumor Cells, Cultured; D019061:src-Family Kinases
D011518:Proto-Oncogene Proteins; D017452:Receptors, IgG; D011505:Protein-Tyrosine Kinases; C496631:HCK protein, human; D051572:Proto-Oncogene Proteins c-hck; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases