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 (PubMed:29779948, PubMed:29775578, PubMed:33398170, PubMed:33398168). 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 (PubMed:29779948, PubMed:29775578, PubMed:33398170, PubMed:33398168). The CRL2(FEM1C) complex specifically recognizes proteins with an arginine at the C-terminus: recognizes and binds proteins ending with -Lys/Arg-Xaa-Arg and -Lys/Arg-Xaa-Xaa-Arg C-degrons, such as SIL1 or OR51B2, leading to their ubiquitination and degradation (PubMed:33398170, PubMed:33398168). The CRL2(FEM1C) complex mediates ubiquitination and degradation of truncated MSRB1/SEPX1 selenoproteins produced by failed UGA/Sec decoding (PubMed:26138980). Promotes ubiquitination and degradation of SLBP (PubMed:28118078). Protein modification; protein ubiquitination. Component of a CRL2 E3 ubiquitin-protein ligase complex, also named ECS (Elongin BC-CUL2/5-SOCS-box protein) complex, composed of CUL2, Elongin BC (ELOB and ELOC), RBX1 and substrate-specific adapter FEM1C. Widely expressed. Highly expressed in kidney, cardiac tissue, skeletal muscle and testis. Expressed at lower levels in other tissues, including cartilage. The first seven ANK repeats at the N-terminus (1-242) are essnetial for recognition of Lys/Arg-Xaa-Arg and -Lys/Arg-Xaa-Xaa-Arg C-degrons. Belongs to the fem-1 family. Was initially thought to be the ortholog of mouse FEM1A.