Analysis of the expression of murine lambda genes transfected into immunocompetent cell lines.
Hybridoma cell lines were transfected with plasmids containing either a rearranged lambda 1 or a rearranged lambda 2 mouse gene. The levels of lambda-chains synthesized by these transfectants were very low or undetectable. Activation of the expression of the lambda 2 gene was achieved artificially by deleting a portion of the region upstream of the promoter. Analogous deletions in the fragment containing the lambda 1 gene did not result in gene activation suggesting that the upstream sequences of lambda 1 and lambda 2 genes have diverged enough to allow differential regulation of their expression. However, both genes were activated by insertion, at a position upstream of the promoter, of a fragment containing the K-chain gene enhancer. These results suggest that the complete set of sequence elements that mediate lambda gene activation during normal B-cell differentiation are not all contained in the fragments of genomic DNA cloned so far, and thus, at least some of them must be located at a considerable distance from the promoter.
Alonso
A
A
Department of Medical Genetics, University of Toronto, Ontario, Canada.
Chang
L A
LA
Murialdo
H
H
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D006825:Hybridomas / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D007146:Immunoglobulin lambda-Chains / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D015533:Transcriptional Activation; D014162:Transfection
D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains