Mad 1 Background Information It is now well established that the nature and relative abundance of individual subunits of different classes of transcription factors can positively or negatively regulate levels of gene expression (1). Myc proteins homodimerize and bind DNA poorly, if at all, at physiological levels (2). Max is a nuclear localized bHLH-Zip protein initially identified by screening a B cell expression library with the bHLH-Zip region of c-Myc (3-6). Max homodimers and the Myc-Max heterodimers bind the sequence CACGTG; however the binding of the heterodimeric complex is stronger than the Max homodimer (3-6). The Max gene products have been identified as (Max) and (Max 9) proteins that differ by a 9 amino acid insertion N-terminal to the basic region (3,6). In contrast to Myc which is highly regulated during progression through the cell cycle, Max is highly stable and is much more abundant than Myc (5). Two members of the bHLH-Zip protein family, designated Mad (7) and Mxi 1 (8) homodimerize poorly but form heterodimeric complexes with Max that have opposing functions to Myc-Max heterodimers with respect to regulation of gene expression.
Mad 1 (MAD1D6H4)
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Mad 1 (MAD1D6H4): sc-81317 Western Blot analysis of human recombinant Mad 1 fusion protein.
