Abstract
Recent studies of murine and human B lymphocytes have shown that crosslinking of surface IgM (sIgM) and sIgD stimulates tyrosine phosphorylation of a set of proteins involved in signal transduction. We investigated tyrosine phosphorylation of the sIg-associated proteins MB-1 and B29, and p75HS1 (HS1), and the association of HS1 with MB-1/B29 heterodimers in normal human B cells and a human B lymphoma cell line, B104. Using immunoprecipitation with anti-phosphotyrosine antibodies (Abs) followed by immunoblotting with anti-MB-1 Abs, anti-B29 Abs or anti-HS1 Abs, we demonstrated that MB-1, B29 and HS1 were tyrosine-phosphorylated after sIgM or sIgD crosslinking. Immunoprecipitation with anti-B29 Abs followed by anti-HS1 Abs immunoblotting revealed that HS1 was associated with MB-1/B29 heterodimers after sIgM or sIgD crosslinking. The results showed that HS1 may play an important role in signal transduction through sIgM and sIgD on human B cells.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adaptor Proteins, Signal Transducing
-
Antigens, CD*
-
B-Lymphocytes / immunology
-
B-Lymphocytes / metabolism*
-
Base Sequence
-
Blood Proteins / metabolism*
-
CD79 Antigens
-
DNA Primers
-
Humans
-
Immunoglobulin D / metabolism
-
Immunoglobulin M / metabolism
-
Membrane Glycoproteins / chemistry
-
Membrane Glycoproteins / metabolism*
-
Molecular Sequence Data
-
Phosphoproteins / metabolism*
-
Phosphorylation
-
Receptors, Antigen, B-Cell / chemistry
-
Receptors, Antigen, B-Cell / immunology*
-
Receptors, Antigen, B-Cell / metabolism*
-
Receptors, Fc / immunology
-
Receptors, Fc / metabolism
-
Receptors, IgG / immunology
-
Receptors, IgG / metabolism
-
Signal Transduction
-
Tumor Cells, Cultured
-
Tyrosine / metabolism*
Substances
-
Adaptor Proteins, Signal Transducing
-
Antigens, CD
-
Blood Proteins
-
CD79 Antigens
-
CD79A protein, human
-
CD79B protein, human
-
DNA Primers
-
HCLS1 protein, human
-
Immunoglobulin D
-
Immunoglobulin M
-
Membrane Glycoproteins
-
Phosphoproteins
-
Receptors, Antigen, B-Cell
-
Receptors, Fc
-
Receptors, IgG
-
immunoglobulin M receptor
-
Tyrosine