Stress associated proteins (SAPs) in plants contain A20-type zinc finger (A20_ZF) domains and are involved with abiotic stress response. A20-type zinc finger domains in animals reportedly recognize ubiquitin as a regulatory signal in cell. However, it remains unclear whether A20_ZF domains in plants perform similar roles. AtSAP5, a SAP from . Arabidopsis thaliana, exhibits a unique sequence feature among 10 AtSAPs harboring A20_ZF domains. The highly conserved diaromatic patch is replaced by the dialipathic patch. Here we investigated whether AtSAP5 recognizes ubiquitin and the roles of the dialipathic patch in ubiquitin binding . in vitro. GST pulldown assay reveals that AtSAP5 binds polyubiquitin rather than monoubiquitin. AtSAP5 shows preferences for linear and K63-linked polyubiquitin chains to K48-linked one. The A20_ZF domain of AtSAP5 is sufficient for linkage-specific polyubiquitin recognition. The dialipathic patch in AtSAP5 plays an important role in K48-linked polyubiquitin recognition. Taken together, our results suggest that AtSAP5 participates in polyubiquitin recognition in plants and that the dialipathic patch in AtSAP5 is critical in binding K48-linked polyubiquitn chains.
|Number of pages
|Biochemical and Biophysical Research Communications
|Published - 2012 Mar 9
Bibliographical noteFunding Information:
We thank Dr. Sangdong Yoo, Dr. Kyung-Hee Paek and Geun-Don Kim for discussions. This work was supported by Mid-career Researcher Program through the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (MEST) ( 2009-0085565 ) and Basic Science Research Program through NRF grants funded by MEST ( 2009-0064219 and 2009-0074586 ).
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology