Transcriptional regulation of the hamster Muc1 gene: identification of a putative negative regulatory element.
The mucin gene Muc1 is expressed in glandular epithelial cells and is involved in lubricative and protective functions. It is also overexpressed in many carcinomas including breast and lung cancer cells. To study the transcriptional regulation of Muc1, we cloned a 2.4-kb fragment containing the promoter region of the hamster Muc1 gene and analyzed it for its ability to mediate transcription. Transcriptional initiation was localized to 22 base pairs downstream of the TATA box. We performed functional analysis of the Muc1 promoter in hamster (HP-1 and Chinese hamster ovary) and human cells (MCF-7, A549, and BEAS-2B) using deletion/reporter constructs. A positive regulatory region between bases -555 and -252 and a putative negative regulatory element (P-NRE) between nucleotides -1,652 and -1,614 were found to be active in transfected cells. The P-NRE contains a yin yang 1 (YY1) transcription factor binding site, and electrophoretic mobility shift assays with HP-1 cell nuclear extract revealed the binding of YY1 to this site. Our data suggest that YY1 may play an inhibitory role in the transcription of the Muc1 gene.
Lee
Insong James
IJ
Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA.
Hyun
Sang Won
SW
Nandi
Asit
A
Kim
K Chul
KC
D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D001665:Binding Sites; D006224:Cricetinae; D050981:Erythroid-Specific DNA-Binding Factors; D005786:Gene Expression Regulation / Q000502:physiology*; D005809:Genes, Regulator / Q000502:physiology*; D006801:Humans; D018396:Mucin-1 / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*; D014407:Tumor Cells, Cultured; D050986:YY1 Transcription Factor
D050981:Erythroid-Specific DNA-Binding Factors; D018396:Mucin-1; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494698:YY1 protein, human