Multiple expression of Ig lambda-chain encoding RNA species in murine plasmacytoma cells.
The murine plasmacytoma MOPC 315, which synthesizes a complete IgA molecule containing lambda 2 light chains, is shown to synthesize a polypeptide related to the lambda 1 light chain. The abnormal lambda 1 polypeptide (m.w. approximately equal to 18,000) is encoded by a shorter polyA+ mRNA than the lambda 1 mRNAs of lambda 1-producing plasmacytomas. Polypeptides containing lambda 1-specific antigenic determinants have been found to be synthesized both in vitro by translations of RNA and in intact cells. HOPC-1, a lambda 1-producing plasmacytoma, was found to synthesize, in addition to the normal lambda 1-encoding mRNA, a lambda 2 RNA of normal length. A lambda 2-producing hybridoma does not appear to synthesize RNA encoding lambda 1 sequences. The results presented here show that more than 1 light chain gene may be transcribed within a single plasmacytoma cell. Although more than 1 light chain gene may be transcribed, the product of only 1 gene appears to be utilized for the synthesis of complete immunoglobulin molecules. This suggests novel mechanisms for the control of immunoglobulin expression.
D000818:Animals; D002460:Cell Line; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000276:immunology; D010954:Plasmacytoma / Q000276:immunology*; D011061:Poly A / Q000276:immunology; D014176:Protein Biosynthesis; D012313:RNA / Q000276:immunology*; D012333:RNA, Messenger / Q000276:immunology; D011817:Rabbits
D007147:Immunoglobulin Light Chains; D007146:Immunoglobulin lambda-Chains; D010455:Peptides; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA