An interaction matrix of BTB domain-containing transcription factors

The Bric-a-brac, Tramtrack, and Broad (BTB) domain is a protein-protein interaction unit found in eukaryotes. It forms a distinct multimeric structure with a large interaction surface. The exposed residues of each monomer are highly variable and can allow dimerization, oligomerization, and interactions with several other proteins such as the corepressors nuclear receptor corepressor (NCOR) and silencing mediator of retinoic acid and thyroid hormone receptor (SMRT). BTB-containing transcription factors are diverse and control various physiological processes ranging from immune system development to cell cycle regulation. To understand the structural basis of these functions, we assessed the interaction networks of these proteins. In this study, we developed specific and systematic assays to screen the interactions between various BTB domain-containing transcription factors and their interaction partners in vitro and in vivo, using surface plasmon resonance (SPR) and fluorescent two-hybrid (F2H) assays. We constructed a homo- and hetero-dimerization matrix of several BTB domains of interest