The Ig kappa 3'-enhancer triggers gene expression in early B lymphocytes but its activity is enhanced on B cell activation.
Ig kappa gene expression is controlled by two enhancers, one located within the major intron (Ei) and the other located downstream of C kappa (E3'). Whereas loss of E3' has previously been shown to diminish kappa expression, we show here that a rearranged kappa transgene lacking Ei is well expressed, even at the pre-B cell stage. This suggests that E3' alone might be sufficient to give properly regulated transcription throughout B cell development. Indeed, we show that a transgene composed of a beta-globin reporter linked to E3' is expressed in a B cell-specific manner, becoming activated at the late pro-B to pre-B cell stage but with dramatically enhanced activity on B cell activation. Thus, E3' becomes active as a transcription enhancer at the stage when V kappa-J kappa rearrangement is being initiated and is sufficient to yield an expression pattern in a linked reporter gene similar to that of fully rearranged kappa genes.
Meyer
K B
KB
Wellcome/CRC Institute of Developmental Biology and Cancer, Cambridge, UK.
Teh
Y M
YM
Neuberger
M S
MS
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000276:immunology*; D005786:Gene Expression Regulation / Q000276:immunology*; D005803:Genes, Immunoglobulin / Q000276:immunology*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics* / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D008822:Mice, Transgenic
D007145:Immunoglobulin kappa-Chains