Distinctive properties of Arabidopsis SUMO paralogues support the in vivo predominant role of AtSUMO1/2 isoforms
Open Access
- 27 May 2011
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 436 (3), 581-590
- https://doi.org/10.1042/bj20101446
Abstract
Protein modification by SUMO (small ubiquitin-related modifier) has emerged as an essential regulatory mechanism in eukaryotes. Even though the molecular mechanisms of SUMO conjugation/deconjugation are conserved, the number of SUMO machinery components and their degree of conservation are specific to each organism. In the present paper, we show data contributing to the notion that the four expressed Arabidopsis SUMO paralogues, AtSUMO1, 2, 3 and 5, have functionally diverged to a higher extent than their human orthologues. We have explored the degree of conservation of these paralogues and found that the surfaces involved in E1-activating enzyme recognition, and E2-conjugating enzyme and SIM (SUMO-interacting motif) non-covalent interactions are well conserved in AtSUMO1/2 isoforms, whereas AtSUMO3 shows a lower degree of conservation, and AtSUMO5 is the most divergent isoform. These differences are functionally relevant, since AtSUMO3 and 5 are deficient in establishing E2 non-covalent interactions, which has not been reported for any naturally occurring SUMO orthologue. In addition, AtSUMO3 is less efficiently conjugated than AtSUMO1/2, and AtSUMO5 shows the lowest conjugation level. A mutagenesis analysis revealed that decreases in conjugation rate and thioester-bond formation are the result of the non-conserved residues involved in E1-activating enzyme recognition that are present in AtSUMO3 and 5. The results of the present study support a role for the E1-activating enzyme in SUMO paralogue discrimination, providing a new mechanism to favour conjugation of the essential AtSUMO1/2 paralogues.Keywords
This publication has 46 references indexed in Scilit:
- Proteome-wide screens for small ubiquitin-like modifier (SUMO) substrates identify Arabidopsis proteins implicated in diverse biological processesProceedings of the National Academy of Sciences of the United States of America, 2010
- Interaction between a Geminivirus Replication Protein and the Plant Sumoylation SystemJournal of Virology, 2004
- MUSCLE: multiple sequence alignment with high accuracy and high throughputNucleic Acids Research, 2004
- The Structure of the APPBP1-UBA3-NEDD8-ATP Complex Reveals the Basis for Selective Ubiquitin-like Protein Activation by an E1Molecular Cell, 2003
- SUMO: ligases, isopeptidases and nuclear poresTrends in Biochemical Sciences, 2003
- A Nuclear Protease Required for Flowering-Time Regulation in Arabidopsis Reduces the Abundance of SMALL UBIQUITIN-RELATED MODIFIER ConjugatesPlant Cell, 2003
- Xanthomonas type III effector XopD targets SUMO‐conjugated proteins in plantaMolecular Microbiology, 2003
- Small Ubiquitin-Like Modifier Modulates Abscisic Acid Signaling in ArabidopsisPlant Cell, 2003
- The Small Ubiquitin-like Modifier (SUMO) Protein Modification System in ArabidopsisPublished by Elsevier BV ,2003
- Functional Heterogeneity of Small Ubiquitin-related Protein Modifiers SUMO-1 versus SUMO-2/3Journal of Biological Chemistry, 2000