Transcription of the human corticotropin-releasing hormone gene in NPLC cells is correlated with Z-DNA formation.
The intron of the corticotropin-releasing hormone (corticoliberin; CRH) gene contains a sequence of over 100 bp of alternating purine/pyrimidine residues. We have used binding of a Z-DNA-specific antibody in metabolically active, permeabilized nuclei to study the formation of Z-DNA in this sequence at various levels of transcription. In the NPLC human primary liver carcinoma cell line, activation of cAMP-dependent pathways increased the level of transcription, while adding glucocorticoids inhibited transcription of the CRH gene. These cells respond in a manner similar to hypothalamic cells. Z-DNA formation in this sequence was detected at the basal level of transcription, as well as after stimulation with forskolin. Inhibition of transcription by dexamethasone abolished Z-DNA formation. Z-DNA formation in the WC gene (c-myc) was affected differently in the same experiment. Thus, changes in Z-DNA formation in the CRH gene are gene specific and are linked to the transcription of the gene.
Wölfl
S
S
Department of Biology, Massachusetts Institute of Technology, Cambridge, 02139, USA.
Martinez
C
C
Rich
A
A
Majzoub
J A
JA
D001483:Base Sequence; D002460:Cell Line; D003346:Corticotropin-Releasing Hormone / Q000235:genetics*; D004247:DNA / Q000096:biosynthesis* / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D005786:Gene Expression Regulation; D016259:Genes, myc; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D014158:Transcription, Genetic
D017931:DNA Primers; D004247:DNA; D003346:Corticotropin-Releasing Hormone