BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Kelch-like protein 25 (KLHL25)
KLHL25, also called ectoderm-neural cortex protein 2 (ENC-2), is a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that is required for translational homeostasis. The BCR(KLHL25) ubiquitin ligase complex acts by mediating ubiquitination of hypophosphorylated EIF4EBP1 (4E-BP1). Cullin3-KLHL25 ubiquitin ligase also targets ATP-citrate lyase (ACLY), a key enzyme for lipid synthesis, for degradation to inhibit lipid synthesis and tumor progression. KLHL25 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.