Fiche publication
Date publication
juin 2020
Journal
Molecular cell
Auteurs
Membres identifiés du Cancéropôle Est :
Dr DAVIDSON Irwin
Tous les auteurs :
Louphrasitthiphol P, Siddaway R, Loffreda A, Pogenberg V, Friedrichsen H, Schepsky A, Zeng Z, Lu M, Strub T, Freter R, Lisle R, Suer E, Thomas B, Schuster-Böckler B, Filippakopoulos P, Middleton M, Lu X, Patton EE, Davidson I, Lambert JP, Wilmanns M, Steingrímsson E, Mazza D, Goding CR
Lien Pubmed
Résumé
It is widely assumed that decreasing transcription factor DNA-binding affinity reduces transcription initiation by diminishing occupancy of sequence-specific regulatory elements. However, in vivo transcription factors find their binding sites while confronted with a large excess of low-affinity degenerate motifs. Here, using the melanoma lineage survival oncogene MITF as a model, we show that low-affinity binding sites act as a competitive reservoir in vivo from which transcription factors are released by mitogen-activated protein kinase (MAPK)-stimulated acetylation to promote increased occupancy of their regulatory elements. Consequently, a low-DNA-binding-affinity acetylation-mimetic MITF mutation supports melanocyte development and drives tumorigenesis, whereas a high-affinity non-acetylatable mutant does not. The results reveal a paradoxical acetylation-mediated molecular clutch that tunes transcription factor availability via genome-wide redistribution and couples BRAF to tumorigenesis. Our results further suggest that p300/CREB-binding protein-mediated transcription factor acetylation may represent a common mechanism to control transcription factor availability.
Mots clés
DNA-binding affinity, E-box, MITF, acetylation, bHLH-LZ, melanocyte, melanoma, transcription factor
Référence
Mol. Cell. 2020 Jun 4;:
