Chromatin interaction mechanism of transcriptional control in vivo.
We have used a kinetic analysis to distinguish possible mechanisms of activation of transcription of the different genes in the human beta globin locus. Based on in situ studies at the single-cell level we have previously suggested a dynamic mechanism of single genes alternately interacting with the locus control region (LCR) to activate transcription. However, those steady-state experiments did not allow a direct measurement of the dynamics of the mechanism and the presence of loci with in situ primary transcript signals from two beta-like genes in cis has left open the possibility that multiple genes in the locus could initiate transcription simultaneously. Kinetic assays involving removal of a block to transcription elongation in conjunction with RNA FISH show that multiple beta gene primary transcript signals in cis represent a transition between alternating transcriptional periods of single genes, supporting a dynamic interaction mechanism.
MGC Department of Cell Biology and Genetics, Erasmus University, PO Box 1738, 3000 DR Rotterdam, The Netherlands.
J
J
Gribnau
E
E
de Boer
T
T
Trimborn
M
M
Wijgerde
E
E
Milot
F
F
Grosveld
P
P
Fraser
D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive / Q000235:genetics; D002478:Cells, Cultured; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D005333:Fetus; D005914:Globins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007700:Kinetics; D008099:Liver; D019901:Locus Control Region / Q000187:drug effects; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*
D002843:Chromatin; D019384:Nucleic Acid Synthesis Inhibitors; D003609:Dactinomycin; D004004:Dichlororibofuranosylbenzimidazole; D005914:Globins