Characterization of a salmon insulin-like growth factor I promoter.
We have identified four transcription initiation sites in the salmon insulin-like growth factor I (IGF-I) gene. Use of the most upstream transcription start site generates a minor mRNA species with a 5' untranslated region (UTR) of approximately 450-550 nucleotides, whereas transcription starting at the downstream initiation sites results in more abundant IGF-I mRNAs with 5'-UTRs approximately 250, 245, and 165 nucleotides in length. No consensus TATA box-like elements are present immediately upstream of the most upstream start site identified, nor is this region particularly GC-rich. Transient expression assays, however, demonstrated orientation-dependent promoter activity in a 386-nucleotide-long fragment containing the major downstream transcription start sites. Additionally, reverse transcriptase polymerase chain reaction (RT-PCR) analyses demonstrated tissue and developmental stage-specific use of the various transcription start sites identified.
Koval
A
A
Department of Biosynthesis of Nucleic Acids, Ukrainian Academy of Sciences, Kiev.
Kulik
V
V
Duguay
S
S
Plisetskaya
E
E
Adamo
M L
ML
Roberts
C T
CT
Leroith
D
D
Kavsan
V
V
D000818:Animals; D001435:Bacteriophages / Q000235:genetics; D001483:Base Sequence; D016466:CHO Cells; D006224:Cricetinae; D018076:DNA, Complementary; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008969:Molecular Sequence Data; D017684:Oncorhynchus kisutch; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D014158:Transcription, Genetic
D018076:DNA, Complementary; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I