Complex interactions with direct repeats of a mitogen-responsive VL30 enhancer.
The RVL-3 VL30 enhancer is an LTR-derived triple direct repeat of 35 base pairs that mediates gene induction in response to several different intracellular signaling pathways. Using mobility shift assays, methylation interference and DNase I footprinting, we have investigated the physical interactions between the RVL-3 enhancer and components of nuclear extracts from Rat-1 cells. Each enhancer repeat unit contains a single binding site. Our studies suggest that binding to the double or triple repeat enhancer is cooperative, involving simultaneous occupation of two sites, with a preference for adjacent sites. Binding cooperativity would have implications for the mechanism of gene activation directed from the native VL30 enhancer.
Pribnow
D
D
Department of Cell and Developmental Biology, School of Medicine, Oregon Health Sciences University, Portland 92201, USA. pribnowd@ohsu.edu
Chen
S L
SL
Zhang
Y
Y
Magun
B E
BE
D000818:Animals; D001483:Base Sequence; D002457:Cell Extracts / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D018983:DNA Footprinting; D003850:Deoxyribonuclease I / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D005786:Gene Expression Regulation; D008745:Methylation; D008934:Mitogens / Q000494:pharmacology; D008969:Molecular Sequence Data; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid; D012190:Retroviridae / Q000187:drug effects / Q000235:genetics*; D015533:Transcriptional Activation
D002457:Cell Extracts; D008934:Mitogens; D004247:DNA; D003850:Deoxyribonuclease I