Polymeric chains of SUMO-2 and SUMO-3 are conjugated to protein substrates by SAE1/SAE2 and Ubc9.
Conjugation of the small ubiquitin-like modifier SUMO-1/SMT3C/Sentrin-1 to proteins in vitro is dependent on a heterodimeric E1 (SAE1/SAE2) and an E2 (Ubc9). Although SUMO-2/SMT3A/Sentrin-3 and SUMO-3/SMT3B/Sentrin-2 share 50% sequence identity with SUMO-1, they are functionally distinct. Inspection of the SUMO-2 and SUMO-3 sequences indicates that they both contain the sequence psiKXE, which represents the consensus SUMO modification site. As a consequence SAE1/SAE2 and Ubc9 catalyze the formation of polymeric chains of SUMO-2 and SUMO-3 on protein substrates in vitro, and SUMO-2 chains are detected in vivo. The ability to form polymeric chains is not shared by SUMO-1, and although all SUMO species use the same conjugation machinery, modification by SUMO-1 and SUMO-2/-3 may have distinct functional consequences.
Tatham
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MH
Institute of Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews KY16 5ST, United Kingdom.
Jaffray
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E
Vaughan
O A
OA
Desterro
J M
JM
Botting
C H
CH
Naismith
J H
JH
Hay
R T
RT
D000595:Amino Acid Sequence; D001483:Base Sequence; D001704:Biopolymers; D002460:Cell Line; D017931:DNA Primers; D004720:Endonucleases; D005656:Fungal Proteins / Q000378:metabolism*; D006801:Humans; D008025:Ligases / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D008969:Molecular Sequence Data; D039502:Nuclear Cap-Binding Protein Complex; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D025841:Small Ubiquitin-Related Modifier Proteins; D013379:Substrate Specificity; D044763:Ubiquitin-Conjugating Enzymes; D014452:Ubiquitins / Q000737:chemistry / Q000378:metabolism*; D000098843:Ubiquitin-Conjugating Enzyme UBC9
D001704:Biopolymers; C100383:CBC2 protein, S cerevisiae; D017931:DNA Primers; D005656:Fungal Proteins; D039502:Nuclear Cap-Binding Protein Complex; D010750:Phosphoproteins; C107849:SAE2 protein, S cerevisiae; C117909:SUMO2 protein, human; C492189:SUMO3 protein, human; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D014452:Ubiquitins; D044763:Ubiquitin-Conjugating Enzymes; D004720:Endonucleases; D008025:Ligases; D000098843:Ubiquitin-Conjugating Enzyme UBC9; D008239:Lysine