Cell type-specific transcriptional enhancement in vitro requires the presence of trans-acting factors.
Cell-specific transcriptional enhancement was observed, depending on the enhancer sequences, using nuclear extracts prepared from B-cells, T-cells and HeLa cells. SV40 enhancer stimulated in vitro transcription up to 15-fold in all three cell extracts, whereas transcriptional potentiation in vitro by IgC mu and LPV enhancers was only seen in B- and T-cell extracts. Thus, the cell type specificity seen in vivo can be reproduced in vitro. The transcriptional enhancement requires the presence of enhancer sequences in cis and also of a common factor interacting in trans with all three enhancer sequences. Interestingly, first experiments indicate the additional presence of cellular factors in T-cell and most prominently in HeLa cell extracts which can reduce the enhancer activity of C mu and LPV.
D001402:B-Lymphocytes / Q000378:metabolism; D002460:Cell Line; D002474:Cell-Free System; D003001:Cloning, Molecular; D004742:Enhancer Elements, Genetic; D005796:Genes; D005809:Genes, Regulator; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007945:Leukemia, Lymphoid; D010957:Plasmids; D012319:RNA Polymerase II / Q000378:metabolism; D013539:Simian virus 40 / Q000235:genetics; D013601:T-Lymphocytes / Q000378:metabolism; D013698:Templates, Genetic; D014158:Transcription, Genetic
D012319:RNA Polymerase II