title: Secretion and processing of an immunoglobulin light chain in Escherichia coli.
abstract: When a cDNA coding for the kappa light chain (L-321) from the mouse MOPC321 myeloma was cloned into Escherichia coli, L-321 antigens were found in both cytoplasmic and periplasmic fractions. In cells synthesizing the intact chain, starting with its signal peptide, the periplasm contained a mature-size immunoglobulin indicating that the eukaryotic signal peptide can initiate secretion and be processed. When the entire cDNA for L-321 (including its signal peptide) was inserted in the gene for bacterial beta-lactamase, processing cleaved only the first bacterial signal sequence of the hybrid protein synthesized. Removal of the beta-lactamase signal peptide was also observed with another beta-lactamase-L-321 hybrid which did not include the immunoglobulin signal peptide and the adjacent part of the variable region. The two hybrid proteins may, however, differ in their mode of secretion.
mesh_terms: D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000276:immunology; D007147:Immunoglobulin Light Chains / Q000235:genetics* / Q000276:immunology; D010957:Plasmids; D011499:Protein Processing, Post-Translational; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D007147:Immunoglobulin Light Chains; D001618:beta-Lactamases