Immunoglobulin heavy-chain enhancer requires one or more tissue-specific factors

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Science  18 Jan 1985:
Vol. 227, Issue 4684, pp. 266-270
DOI: 10.1126/science.3917575


Enhancer sequences are regulatory regions that greatly increase transcription of certain eukaryotic genes. An immunoglobulin heavy-chain variable gene segment is moved from a region lacking enhancer activity to a position adjacent to the known heavy-chain enhancer early in B-cell maturation. In lymphoid cells, the heavy-chain and SV40 enhancers bind a common factor essential for enhancer function. In contrast, fibroblast cells contain a functionally distinct factor that is used by the SV40 but not by the heavy-chain enhancer. The existence of different factors in these cells may explain the previously described lymphoid cell specificity of the heavy-chain enhancer.