Transcriptional repressor protein YY1 (YY1)

Multifunctional transcription factor that exhibits positive and negative control on a large number of cellular and viral genes by binding to sites overlapping the transcription start site. Binds to the consensus sequence 5'-CCGCCATNTT-3'; a few genes have been demonstrated to contain a longer binding motif allowing enhanced binding; the first CG dinucleotide can be methylated greatly reducing the binding affinity.

The impact on transcription regulation is depending on the context in which it binds and diverse mechanisms of action include direct activation or repression, indirect activation or repression via cofactor recruitment, or activation or repression by disruption of binding sites or conformational DNA changes. Its activity is regulated by transcription factors and cytoplasmic proteins that have been shown to abrogate or completely inhibit YY1-mediated activation or repression.