The SUMO components in rheumatoid arthritis.

Small ubiquitin-like modifier (SUMO) proteins can reversibly attach covalently or non-covalently to lysine residues of various substrates. The processes are named SUMOylation and de-SUMOylation, which maintain a dynamic balance in the physiological state, and are regulated by SUMO components. However, the dysregulation of components disturbs the balance and alters the functions of target proteins, which causes the occurrence of diseases. To date, certain SUMO components, including SUMO-1, SUMO-2/3, SAE1/Uba2, Ubc9, PIASs (protein inhibitors of activated signal transducer and activator of transcription) and SENPs (SUMO-specific proteases), have been found to participate in the pathogenesis of RA and their potential value as therapeutic targets also have been highlighted. In addition, single nucleotide polymorphisms (SNPs) in the SUMO components have been reported to be associated with disease susceptibility. Until now, only the SNP site of SUMO-4 has been reported in RA. Here we provided a systematic overview of the general characteristics of SUMO components and highlighted a summary of their impact on RA.