Cloning, genomic organization, expression, and effect on beta-casein promoter activity of a novel isoform of the mouse Oct-1 transcription factor.
The ubiquitously expressed transcription factor Oct-1, a member of the POU domain factors, is involved in the regulation of expression of many tissue-specific and house-keeping genes. Multiple alternatively spliced isoforms of Oct-1 have been identified in human and mouse cells. The expression patterns of these isoforms and the analysis of their genomic organization and structure have suggested that the structural variation of Oct-1 isoforms may be important in conferring target and tissue specificity to its transcriptional activity. In this study, we have cloned and sequenced a new mouse Oct-1 isoform, named mOct-1Z. This novel isoform differs markedly at the C-terminus from the previously identified Oct-1 isoforms A, B, and C. It is generated by alternative splicing from the Oct-1 gene and its transcript exhibits a frameshift followed by an early stop codon, thus, its predicted protein has a distinct, much shorter C-terminal tail. However, this truncated isoform could still effectively bind to a consensus Oct-1 motif oligonucleotide and, like Oct-1B, activated the basal promoter activity of the mouse beta-casein gene. Oct-1Z is another ubiquitously expressed Oct-1 isoform, its transcript being detected in all mouse tissues examined, including the mammary gland, liver, lung, kidney, spleen, small intestine mucosa, uterus, and ovary.
Zhao
Feng-Qi
FQ
Lactation and Mammary Gland Biology Group, Department of Animal Science, University of Vermont, Burlington, VT 05405, USA. Feng-Qi.Zhao@uvm.edu
Zheng
Yucai
Y
Dong
Bing
B
Oka
Takami
T
D024506:5' Flanking Region / Q000235:genetics; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002364:Caseins / Q000235:genetics*; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D005796:Genes / Q000235:genetics; D051863:Host Cell Factor C1; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D050811:Octamer Transcription Factor-1; D009841:Oligonucleotides / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
D002364:Caseins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C497693:Hcfc1 protein, mouse; D051863:Host Cell Factor C1; D050811:Octamer Transcription Factor-1; D009841:Oligonucleotides; C494166:Pou2f1 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D008156:Luciferases