The enhancement of specific gene transcription in isolated nuclei by added HeLa whole cell extract.

Transcription was carried out in isolated rat liver nuclei by endogenous RNA polymerase with the addition of HeLa whole cell extract (HWCE) in the presence of nucleoside 5'-[gamma-S]triphosphate. The resulting 5'-gamma-thiophosphate on the synthesized RNA allows separation of in vitro initiated RNA from bulk RNA by mercury-agarose chromatography. HWCE not only increased initiation of new RNA chains greater than 3 times but also had no effect on the RNA synthesis by RNA polymerase II. The initiation of transcription of albumin and alpha-fetoprotein genes in an isolated nuclei system was selectively enhanced by HWCE. Using this system, we studied the effect of glucocorticoid on albumin and alpha-fetoprotein gene expression in vitro.