Substrate-recognition component of a Cul2-RING (CRL2 E3 ubiquitin-protein ligase complex of the DesCEND (destruction via C-end degrons pathway, which recognizes a C-degron located at the extreme C terminus of target proteins, leading to their ubiquitination and degradation. The C-degron recognized by the DesCEND pathway is usually a motif of less than ten residues and can be present in full-length proteins, truncated proteins or proteolytically cleaved forms. The CRL2(KLHDC2 complex specifically recognizes proteins with a diglycine (Gly-Gly at the C-terminus, leading to their ubiquitination and degradation. The CRL2(KLHDC2 complex mediates ubiquitination and degradation of truncated SELENOK and SELENOS selenoproteins produced by failed UGA/Sec decoding, which end with a diglycine. The CRL2(KLHDC2 complex also recognizes proteolytically cleaved proteins ending with Gly-Gly, such as the N-terminal fragment of USP1, leading to their degradation. May also act as an indirect repressor of CREB3-mediated transcription by interfering with CREB3-DNA-binding.
