The products of pre-B cell-specific genes (lambda 5 and VpreB) and the immunoglobulin mu chain form a complex that is transported onto the cell surface.
We constructed expression vectors coding for the two pre-B-specific genes, VpreB and lambda 5, and transfected them together with a mu vector (mu tm) into Ig- myeloma cells. In a transfectant expressing all three introduced genes, the mu tm chain is transported on the cell surface. A biochemical analysis demonstrated that, in these cells, the mu tm chain is associated noncovalently with an 18-kD protein and covalently with a 22-kD protein, which are most likely the products of VpreB and lambda 5, respectively. Our results, thus, strongly suggest that the products of lambda 5 and VpreB bind to mu chains and have the same capacity as conventional Ig L chains to allow surface expression of mu chains.
Tsubata
T
T
Max-Planck Institute for Immunobiology, Freiburg, Federal Republic of Germany.
Reth
M
M
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005803:Genes, Immunoglobulin; D005822:Genetic Vectors; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics* / Q000378:metabolism; D007146:Immunoglobulin lambda-Chains / Q000235:genetics* / Q000378:metabolism; D007148:Immunoglobulin mu-Chains / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D014162:Transfection
D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains; D007148:Immunoglobulin mu-Chains