BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch repeat and BTB domain-containing protein 2 (KBTBD2)
KBTBD2, also called BTB and kelch domain-containing protein 1 (BKLHD1), plays an essential role in the regulation of insulin-signaling pathway. It is a BTB-Kelch family substrate recognition subunit of the Cullin-3-based E3 ubiquitin ligase, which targets p85alpha, the regulatory subunit of the phosphoinositol-3-kinase (PI3K) heterodimer, causing p85alpha ubiquitination and proteasome-mediated degradation. It contains a BTB domain and kelch repeats, characteristics of a kelch family protein. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.