Mad: a heterodimeric partner for Max that antagonizes Myc transcriptional activity.
Myc family proteins appear to function through heterodimerization with the stable, constitutively expressed bHLH-Zip protein, Max. To determine whether Max mediates the function of regulatory proteins other than Myc, we screened a lambda gt11 expression library with radiolabeled Max protein. One cDNA identified encodes a new member of the bHLH-Zip protein family, Mad. Human Mad protein homodimerizes poorly but binds Max in vitro, forming a sequence-specific DNA binding complex with properties very similar to those of Myc-Max. Both Myc-Max and Mad-Max heterocomplexes are favored over Max homodimers, and, unlike Max homodimers, the DNA binding activity of the heterodimers is unaffected by CKII phosphorylation. Mad does not associate with Myc or with representative bHLH, bZip, or bHLH-Zip proteins. In vivo transactivation assays suggest that Myc-Max and Mad-Max complexes have opposing functions in transcription and that Max plays a central role in this network of transcription factors.[1]References
- Mad: a heterodimeric partner for Max that antagonizes Myc transcriptional activity. Ayer, D.E., Kretzner, L., Eisenman, R.N. Cell (1993) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
