Activator proteins which regulate immunoglobulin heavy chain gene transcription in B lymphocytes.

While our results do not completely explain the B-cell specificity or other regulated aspects of IgH transcription, they show that IgH transcriptional factors belong to several different DNA-binding families which are capable of dimerization. It may be that formation of heteromultimers provides an additional level of regulation which might confer functional tissue specificity. Our results also suggest that enhancers and promoters may interact through protein-protein interactions, looping out the intervening DNA. Finally, we have shown that the same protein may regulate several genes including IgH and c-myc, indicating that transcriptional regulatory mechanisms for different genes are both complex and interconnected.