The tripartite DNA element responsible for diet-induced rat fatty acid synthase (FAS) regulation.
We investigated which region of the 5'-flanking sequence of the rat fatty acid synthase (FAS)-encoding gene could be responsible for its nutritionally regulated expression. Diet-induced differences in chromatin structure were determined by DNase I treatment of intact nuclei from hepatic tissue. A low-fat diet results in a different pattern of DNase I-hypersensitive sites (HS) in the chromatin of the FAS promoter (pFAS) from that seen when the nuclear extract was prepared from the livers of normally fed rats. The protein-binding properties of the region defined by DNase I hypersensitivity were tested by gel retardation. A putative cis-acting element with a tripartite structure, 5'-GCCT, 6-bp spacer and a 3'-palindrome, could be localized between bp -518 to -495 in pFAS. Competition experiments with oligodeoxyribonucleotides (oligos) representing subfragments of this cis-element showed that the requirement for structure is stricter than that for sequence. This element could be one of the termini of the insulin-induced signal cascade.
Institut für Mikrobiologie und Biochemie, Universität Erlangen-Nürnberg, Germany.
K
K
Roder
H
H
Klein
H
H
Kranz
K F
KF
Beck
M
M
Schweizer
D000818:Animals; D001483:Base Sequence; D002843:Chromatin / Q000378:metabolism; D004247:DNA; D003850:Deoxyribonuclease I / Q000378:metabolism; D004032:Diet; D004591:Electrophoresis, Polyacrylamide Gel; D064429:Fatty Acid Synthases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D007328:Insulin / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping
D002843:Chromatin; D007328:Insulin; D004247:DNA; D064429:Fatty Acid Synthases; D003850:Deoxyribonuclease I