These authors contributed equally to this work.
Functional characterization of the SIZ/PIAS-type SUMO E3 ligases, OsSIZ1 and OsSIZ2 in rice
Article first published online: 18 JUN 2010
© 2010 Blackwell Publishing Ltd
Plant, Cell & Environment
Volume 33, Issue 11, pages 1923–1934, November 2010
How to Cite
PARK, H. C., KIM, H., KOO, S. C., PARK, H. J., CHEONG, M. S., HONG, H., BAEK, D., CHUNG, W. S., KIM, D. H., BRESSAN, R. A., LEE, S. Y., BOHNERT, H. J. and YUN, D.-J. (2010), Functional characterization of the SIZ/PIAS-type SUMO E3 ligases, OsSIZ1 and OsSIZ2 in rice. Plant, Cell & Environment, 33: 1923–1934. doi: 10.1111/j.1365-3040.2010.02195.x
- Issue published online: 18 JUN 2010
- Article first published online: 18 JUN 2010
- Received 28 April 2010; received in revised form 3 June 2010; accepted for publication 4 June 2010
- Oryza sativa;
- SIZ/PIAS-type SUMO E3-ligase;
- stress response;
Sumoylation is a post-translational regulatory process in diverse cellular processes in eukaryotes, involving conjugation/deconjugation of small ubiquitin-like modifier (SUMO) proteins to other proteins thus modifying their function. The PIAS [protein inhibitor of activated signal transducers and activators of transcription (STAT)] and SAP (scaffold attachment factor A/B/acinus/PIAS)/MIZ (SIZ) proteins exhibit SUMO E3-ligase activity that facilitates the conjugation of SUMO proteins to target substrates. Here, we report the isolation and molecular characterization of Oryza sativa SIZ1 (OsSIZ1) and SIZ2 (OsSIZ2), rice homologs of Arabidopsis SIZ1. The rice SIZ proteins are localized to the nucleus and showed sumoylation activities in a tobacco system. Our analysis showed increased amounts of SUMO conjugates associated with environmental stresses such as high and low temperature, NaCl and abscisic acid (ABA) in rice plants. The expression of OsSIZ1 and OsSIZ2 in siz1-2 Arabidopsis plants partially complemented the morphological mutant phenotype and enhanced levels of SUMO conjugates under heat shock conditions. In addition, ABA-hypersensitivity of siz1-2 seed germination was partially suppressed by OsSIZ1 and OsSIZ2. The results suggest that rice SIZ1 and SIZ2 are able to functionally complement Arabidopsis SIZ1 in the SUMO conjugation pathway. Their effects on the Arabidopsis mutant suggest a function for these genes related to stress responses and stress adaptation.