The 3' Igkappa enhancer contains RNA polymerase II promoters: implications for endogenous and transgenic kappa gene expression.
We have created a kappa transgene in which a polymerase (pol) III promoter replaces the pol II promoter. Two independent transgenic lines show somatic hypermutation of the transgene in B cells from hyperimmunized mice. Both lines transcribe transgenes from the pol III promoter in the liver. However, in spleen and spleen B cell-derived hybridomas, they also transcribe mRNA from pol II promoters located within the 3' kappa enhancer of the preceding transgene copy in a tandem transgene array. The findings demonstrate that in an array of multiple transgenes the expression (and somatic hypermutation) of an individual transgene copy must be considered in the context of the other copies. We also show that sequences around the 3' kappa enhancer in endogenous genes are transcribed. The possible role of these promoters in endogenous kappa gene expression is discussed. An unrelated finding in this study was a novel RNA splice in one hybridoma.
Shen
H M
HM
Biochemistry and Molecular Biology, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA.
Peters
A
A
Kao
D
D
Storb
U
U
D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004742:Enhancer Elements, Genetic; D015870:Gene Expression; D005803:Genes, Immunoglobulin; D006825:Hybridomas; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000235:genetics*; D012320:RNA Polymerase III / Q000235:genetics; D012326:RNA Splicing
D017931:DNA Primers; D007145:Immunoglobulin kappa-Chains; D004247:DNA; D012319:RNA Polymerase II; D012320:RNA Polymerase III