Tissue-specific expression of rat pyruvate kinase L/chloramphenicol acetyltransferase fusion gene in transgenic mice and its regulation by diet and insulin.
We produced transgenic mice carrying about 3 kb of the 5'-flanking sequence of the rat pyruvate kinase L gene linked to the chloramphenicol acetyltransferase (CAT) structural gene. Expression of the transgene was observed only in tissues in which the endogenous L-type pyruvate kinase is expressed. Dietary glucose or insulin induced similar increases in the levels of CAT and L-type pyruvate kinase mRNAs in the liver. However, the fructose-induced level of CAT mRNA was about 3- and 6- fold lower than those of endogenous L-type pyruvate kinase mRNA in the liver and kidney, respectively, confirming our previous finding that stabilization of the transcripts of the pyruvate kinase L gene is an important regulatory step in fructose induction, especially in the kidney. Thus we conclude that all the cis-acting elements responsible for tissue-specific expression of the L-type pyruvate kinase and its stimulation by dietary components and insulin are localized in the sequence from about nucleotide -3000 to +37 in the pyruvate kinase L gene.
Department of Nutrition and Physiological Chemistry, Osaka University Medical School, Japan.
K
K
Yamada
T
T
Noguchi
J
J
Miyazaki
T
T
Matsuda
M
M
Takenaka
K
K
Yamamura
T
T
Tanaka
D000818:Animals; D015152:Blotting, Northern; D015500:Chloramphenicol O-Acetyltransferase; D004032:Diet; D015971:Gene Expression Regulation, Enzymologic; D007328:Insulin / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D011770:Pyruvate Kinase / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011993:Recombinant Fusion Proteins; D012045:Regulatory Sequences, Nucleic Acid; D014018:Tissue Distribution; D014158:Transcription, Genetic
D007328:Insulin; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase; D011770:Pyruvate Kinase