Distinct and overlapping sets of SUMO-1 and SUMO-2 target proteins revealed by quantitative proteomics.
The small ubiquitin-like modifier (SUMO) family in vertebrates includes three different family members that are conjugated as post-translational modifications to target proteins. SUMO-2 and -3 are nearly identical but differ substantially from SUMO-1. We used quantitative proteomics to investigate the target protein preferences of SUMO-1 and SUMO-2. HeLa cells were established that stably express His6-SUMO-1 or His6-SUMO-2. These cell lines and control HeLa cells were labeled with stable arginine isotopes, and His6-SUMOs were enriched from lysates using immobilized metal affinity chromatography. 53 SUMO-conjugated proteins were identified, including 44 novel SUMO targets. 25 proteins were preferentially conjugated to SUMO-1, 19 were preferentially conjugated to SUMO-2, and nine proteins were conjugated to both SUMO-1 and SUMO-2. SART1 was confirmed by immunoblotting to have both SUMO-1- and SUMO-2-linked forms at similar levels. SUMO-1 and SUMO-2 are thus shown to have distinct and overlapping sets of target proteins, indicating that SUMO-1 and SUMO-2 may have both redundant and non-redundant cellular functions. Interestingly, 14 of the 25 SUMO-1-conjugated proteins contain zinc fingers. Although both SUMO family members play roles in many cellular processes, our data show that sumoylation is strongly associated with transcription because nearly one-third of the identified target proteins are putative transcriptional regulators.
Vertegaal
Alfred C O
AC
Department of Molecular Cell Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands. vertegaal@lumc.nl
Andersen
Jens S
JS
Ogg
Stephen C
SC
Hay
Ronald T
RT
Mann
Matthias
M
Lamond
Angus I
AI
D002846:Chromatography, Affinity; D006367:HeLa Cells; D006801:Humans; D046912:Multiprotein Complexes / Q000302:isolation & purification*; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D040901:Proteomics / Q000379:methods*; D025842:SUMO-1 Protein / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D014162:Transfection
D046912:Multiprotein Complexes; D025842:SUMO-1 Protein; C117909:SUMO2 protein, human; D025841:Small Ubiquitin-Related Modifier Proteins