5' flanking and first intron sequences of the human beta-actin gene required for efficient promoter activity.
We have identified a CCAAT box element that is required for the efficient transcription of the human beta-actin gene. Both in vivo transient transfection assays in cultured HeLa cells and in vitro run-off transcription assays in HeLa whole cell extracts demonstrated the requirement of this element for efficient promoter activity. A gel mobility shift assay revealed a Hela nuclear factor that specifically interacted with the beta-actin CCAAT element in vitro; mutation of the first three base pairs of the CCAAT pentanucleotide abolished binding of this factor. Competition gel shift experiments revealed that three sequence elements located within the beta-actin promoter, each containing a CC(A/T)6GG motif similar to that contained within the c-fos serum response element, were able to bind a different nuclear factor, serum response factor (SRF). One of these CC(A/T)6GG motifs is contained within a first intron fragment that enhanced transcription from a heterologous promoter in vivo.
Frederickson
R M
RM
Division of Biological Research, Ontario Cancer Institut, Toronto, Canada.
Micheau
M R
MR
Iwamoto
A
A
Miyamoto
N G
NG
D000199:Actins / Q000235:genetics*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism; D005796:Genes; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014162:Transfection
D000199:Actins; D004268:DNA-Binding Proteins