F-box only protein 31 (FBXO31)

F-box only protein 31 (FBXO31) is a member of the F-box protein family, acting as a substrate receptor within the SCF (Skp1-Cul1-F-box protein) E3 ubiquitin ligase complex[1][3][4]. FBXO31 is distinguished by a unique substrate-binding domain comprising two β-barrel motifs and a zinc-binding CHCH-type structural motif[1]. It recognizes substrates primarily via their modified C-termini, including cyclin D1 (phosphorylated or truncated) and C-terminal amidated peptides, initiating ubiquitination and degradation in response to cell stress[1][2][3][4]. FBXO31 is essential for controlling cell cycle transitions, particularly enforcing G1 arrest by mediating degradation of cyclin D1 and cyclin A during DNA damage or genotoxic stress[2][3]. It additionally promotes DNA damage responses by facilitating MDM2 degradation and p53 pathway activation[3]. FBXO31 has been implicated as a putative breast cancer tumor suppressor, with dysregulated function associated with unchecked proliferation and genomic instability[3]. There are currently no drugs known to directly target FBXO31, and therapeutically relevant safety concerns are not described in primary sources.

Other names

FBX31FBX14PP2386FBXO14Fbx31MGC15419MRT45SCF ubiquitin ligase specificity factorputative breast cancer tumor-suppressor