Mastermind-like proteins are transcriptional coactivators that were first described as integral part of the Notch signalling pathway [1] but also involved in Wnt/beta-catenin, Sonic Hh and Hippo pathways [4]. MAML family consists of MAML1, 2 and 3, which have a conserved N-terminal basic domain (Pfam:PF09596) but their amino acid sequence outside this region is more divergent which suggests that MAML2 and MAML3 may have different functions. This entry represents the transactivation domain 2 (TAD2) found at the C-terminal of Mastermind-like protein 1/3 (MAML1/3). TAD2 from MAML1 enhances the phosphorylation of CBP/p300 and ICN, required for Notch induced transcription [1-4]. This is a glutamine rich domain that govern the MAML1 transcriptional activity [1]. This domain directly recruits the cyclin C:CDK8 (cyclin-dependent kinase 8) complex that inhibits Notch signalling by promoting phosphorylation-dependent ubiquitination of nuclear ICN and its sequential proteasomal degradation [4].

1: Mastermind mediates chromatin-specific transcription and turnover of the Notch enhancer complex. Fryer CJ, Lamar E, Turbachova I, Kintner C, Jones KA; Genes Dev. 2002;16:1397-1411. PMID:12050117

2: MAML1, a human homologue of Drosophila mastermind, is a transcriptional co-activator for NOTCH receptors. Wu L, Aster JC, Blacklow SC, Lake R, Artavanis-Tsakonas S, Griffin JD; Nat Genet. 2000;26:484-489. PMID:11101851

3: Identification of a family of mastermind-like transcriptional coactivators for mammalian notch receptors. Wu L, Sun T, Kobayashi K, Gao P, Griffin JD; Mol Cell Biol. 2002;22:7688-7700. PMID:12370315

4: A Dynamic Role of Mastermind-Like 1: A Journey Through the Main (Path)ways Between Development and Cancer. Zema S, Pelullo M, Nardozza F, Felli MP, Screpanti I, Bellavia D; Front Cell Dev Biol. 2020;8:613557. PMID:33425921