Ectoderm-neural cortex protein 1 (ENC1), also known as kelch-like protein 37 (KLHL37), is expressed in the central nervous system (CNS), where it interacts with actin and contributes to the organisation of the cytoskeleton during the specification of neural fate []. ENC1 functions as a negative regulator of transcription factor Nrf2 (a regulator of a cellular defense mechanism against environmental insults) through suppressing Nrf2 protein translation []. It plays a pivotal role in neuronal and adipocyte differentiation [].The KLHL (Kelch-like) proteins generally have a BTB/POZ domain, a BACK domain, and five to six Kelch motifs. They constitute a subgroup at the intersection between the BTB/POZ domain and Kelch domain superfamilies. The BTB/POZ domain facilitates protein binding [], while the Kelch domain (repeats) form β-propellers. The Kelch superfamily of proteins can be subdivided into five groups: (1) N-propeller, C-dimer proteins, (2) N-propeller proteins, (3) propeller proteins, (4) N-dimer, C-propeller proteins, and (5) C-propeller proteins. KLHL family members belong to the N-dimer, C-propeller subclass of Kelch repeat proteins []. In addition to BTB/POZ and Kelch domains, the KLHL family members contain a BACK domain, first described as a 130-residue region of conservation observed amongst BTB-Kelch proteins []. Many of the Kelch-like proteins have been identified as adaptors for the recruitment of substrates to Cul3-based E3 ubiquitin ligases [, ].
