Approximately 1 kilobase of sequence 5' to the two myosin light-chain 1f/3f gene cap sites is sufficient for differentiation-dependent expression.
Approximately 1 kilobase of genomic DNA from the chicken fast myosin light-chain 1f/3f gene 5' to the transcriptional start sites for each light-chain mRNA was sufficient for differentiation-dependent, tissue-restricted expression. This was determined in primary chick myoblast cultures transfected with the chloramphenicol acetyltransferase (CAT) expression vector p8CAT containing these 5'-flanking sequences. The expression of CAT activity from both light-chain promoters was 10- to 20-fold higher in differentiated myotubes than in fibroblasts or myoblasts grown in bromodeoxyuridine. In contrast, the beta-actin and Rous sarcoma virus promoters joined to the CAT gene were expressed equally in all cell backgrounds tested. Even though the relative timing of light-chain 1f and 3f expression was altered, tissue-restricted, differentiation-dependent expression of the light-chain mRNAs was maintained with these 5' cis-acting sequence elements.
Billeter
R
R
Laboratory of Biochemistry, National Cancer Institute, Bethesda, Maryland 20892.
Quitschke
W
W
Paterson
B M
BM
D000123:Acetyltransferases / Q000235:genetics; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D002645:Chickens; D015500:Chloramphenicol O-Acetyltransferase; D005786:Gene Expression Regulation; D005796:Genes; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D009218:Myosins / Q000096:biosynthesis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012315:RNA Caps / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D012315:RNA Caps; D012333:RNA, Messenger; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase; D009218:Myosins