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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1999-6-25
pubmed:abstractText
The observation that cyclin B1 protein and mRNAs are down-regulated in terminally differentiated (TD) C2C12 cells, suggested us to investigate the transcriptional regulation of the cyclin B1 gene in these cells. Transfections of cyclin B1 promoter constructs indicate that two CCAAT boxes support cyclin B1 promoter activity in proliferating cells. EMSAs demonstrate that both CCAAT boxes are recognized by the trimeric NF-Y complex in proliferating but not in TD cells. Transfecting a dominant-negative mutant of NF-YA we provide evidence that NF-Y is required for maximal promoter activity. Addition of recombinant NF-YA to TD C2C12 nuclear extracts restores binding activity in vitro, thus indicating that the loss of NF-YA in TD cells is responsible for the lack of the NF-Y binding to the CCAAT boxes. Consistent with this, we found that the NF-YA protein is absent in TD C2C12 cells. In conclusion, our data demonstrate that NF-Y is required for cyclin B1 promoter activity. We also demonstrate that cyclin B1 expression is regulated at the transcriptional level in TD C2C12 cells and that the switch-off of cyclin B1 promoter activity in differentiated cells depends upon the loss of a functional NF-Y complex. In particular the loss of NF-YA protein is most likely responsible for its inactivation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2818-27
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:10362252-Animals, pubmed-meshheading:10362252-CCAAT-Binding Factor, pubmed-meshheading:10362252-CCAAT-Enhancer-Binding Proteins, pubmed-meshheading:10362252-Cell Differentiation, pubmed-meshheading:10362252-Cell Division, pubmed-meshheading:10362252-Cells, Cultured, pubmed-meshheading:10362252-Cyclin B, pubmed-meshheading:10362252-Cyclin B1, pubmed-meshheading:10362252-DNA-Binding Proteins, pubmed-meshheading:10362252-Down-Regulation, pubmed-meshheading:10362252-Gene Expression Regulation, pubmed-meshheading:10362252-Mice, pubmed-meshheading:10362252-Muscle, Skeletal, pubmed-meshheading:10362252-Promoter Regions, Genetic, pubmed-meshheading:10362252-Recombinant Proteins, pubmed-meshheading:10362252-Regulatory Sequences, Nucleic Acid, pubmed-meshheading:10362252-Transcription, Genetic, pubmed-meshheading:10362252-Transcription Factors
pubmed:year
1999
pubmed:articleTitle
Down-regulation of cyclin B1 gene transcription in terminally differentiated skeletal muscle cells is associated with loss of functional CCAAT-binding NF-Y complex.
pubmed:affiliation
Laboratorio di Oncogenesi Molecolare, CRS-IRE, Rome, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't