Mediator of RNA polymerase II transcription subunit 15 KIX domain (MED15 KIX)

The Mediator of RNA polymerase II transcription subunit 15 (MED15) KIX domain is a specialized protein-protein interaction module located within the Mediator complex, a massive multi-protein assembly that bridges DNA-bound transcription factors to the RNA polymerase II machinery (UniProt Q96RN5). The KIX domain specifically functions as a docking site for the transactivation domains of various transcription factors, most notably the Sterol Regulatory Element-Binding Proteins (SREBPs), which are master regulators of lipid and cholesterol metabolism (PubMed: 25154354). Beyond metabolism, the MED15 KIX domain is implicated in several signaling pathways, including TGF-beta and p53-mediated stress responses. In clinical oncology, MED15 is frequently overexpressed and is associated with tumor recurrence, metastasis, and resistance to therapies in prostate and breast cancers (PubMed: 24631377). Consequently, the KIX domain has emerged as a high-priority therapeutic target for the development of small-molecule inhibitors designed to disrupt pathological protein-protein interactions (PubMed: 28846511). Current research focuses on identifying selective ligands that can block these interactions to treat metabolic diseases and advanced malignancies without affecting the structurally similar KIX domains of other essential coactivators like CBP or p300 (PubMed: 31216345).

Other names

Mediator complex subunit 15Activator-recruited cofactor 105 kDa componentARC105PC2 glutamine/rich-associated proteinPCQAPTIG-1CTG7ATGR1

Inhibition of protein-protein interactions (PPI) between the KIX domain and transactivation domains of transcription factors such as SREBP, p53, or GATA.