Developmentally regulated association of a 56-kD member of the surface immunoglobulin M receptor complex.

摘要: Immature and mature B cells differ in the signals generated transduced through their antigen receptor, surface immunoglobulin M (sIgM). Whereas sIgM on initiate a program leading to positive activation of these cells, signaling this receptor at immature stage development leads state induced unresponsiveness or tolerance. Our previous studies have described developmental differences transmembrane that are independent ligand-receptor affinity. In an attempt understand molecular basis for between we analyzed complex neonatal adult mouse splenic cells. While previously components do not exhibit marked developmentally regulated association with sIgM, identified 56-kD protein associates (antigen-responsive), but (tolerance-sensitive) This (p56) as homodimer, is constitutively phosphorylated tyrosine, coimmunoprecipitated IgM IgD. The observed inability iodinate p56 suggests it intracellular component complex. Based upon its migration one- two-dimensional gel electrophoresis show, however, distinct from blk, lyn, fyn src family kinases been shown be associated participation cell role differential mediated via