TOPLESS (TPL)

TOPLESS (TPL) is a foundational transcriptional corepressor in plants, primarily characterized in the model organism Arabidopsis thaliana. It is a member of the evolutionarily conserved Groucho/Tup1 family, which includes human homologs such as Transducin-like enhancer of split (TLE) and Transducin beta-like 1 (TBL1) [7.2.1, 7.3.1]. TPL acts as a central hub in multiple plant signaling pathways, including those for auxin, jasmonate, and strigolactone, by bridging DNA-binding transcription factors with chromatin-remodeling machinery [7.5.1, 9.2.1]. It typically interacts with repressors containing an Ethylene-responsive element binding factor-associated Amphiphilic Repression (EAR) motif through its N-terminal LisH and CTLH domains [7.1.2, 8.2.2]. While TPL is not a direct therapeutic target in human medicine, it is extensively utilized in synthetic biology and drug discovery research, particularly as a critical component of the auxin-inducible degron (AID) system for targeted protein degradation in mammalian cells [7.1.1, 8.5.3].

Other names

TPLTOPLESS-relatedTPRAtTPLGroucho/Tup1-like corepressor

Recruits histone deacetylases (HDACs) and interacts with the Mediator complex (specifically Med21 and Med10) to inhibit RNA polymerase II-mediated transcription initiation and elongation [7.2.1, 8.2.1].