TY - JOUR
T1 - Arabidopsis SAP5 functions as a positive regulator of stress responses and exhibits E3 ubiquitin ligase activity
AU - Kang, Miyoung
AU - Fokar, Mohamed
AU - Abdelmageed, Haggag
AU - Allen, Randy D.
N1 - Funding Information:
Acknowledgments The authors thank Dr. Yuhong Tang and Mr. Stacy Allen at the Noble Foundation Microarray Facility for micro-array analyses and Ms. Karen Flowers at the Noble Foundation Greenhouse Facility for assistance with plant production. This work was funded in part by grants from the Oklahoma Center for the Advancement of Science & Technology and start-up funds from the Noble Foundation and the Walter Sitlington Foundation.
PY - 2011/3
Y1 - 2011/3
N2 - AtSAP5, one of approximately 14 members of the Stress Associated Protein gene family in Arabidopsis, was identified by its expression in response to salinity, osmotic, drought and cold stress. AtSAP5 shows strong homology to OSISAP1, an A20/AN1-type zinc finger protein implicated in stress tolerance in rice. To evaluate the function of AtSAP5 in the regulation of abiotic stress responses, transgenic Arabidopsis plants that over-express AtSAP5 (35S::AtSAP5) were characterized, along with wild-type and T-DNA knock-down plants. Plants that over-express AtSAP5 showed increased tolerance to environmental challenges including salt stress, osmotic stress and water deficit. Comparison of gene expression patterns between 35S::AtSAP5 transgenic plants and wild-type plants under normal conditions and water deficit stress indicated that over-expression of AtSAP5 correlates with up-regulation of drought stress responsive gene expression. Analysis of transgenic plants that express GFP-AtSAP5 showed that it is localized primarily in nuclei of root cells and recombinant AtSAP5 has E3 ubiquitin ligase activity in vitro. These results indicate that AtSAP5 has E3 ligase activity and acts as a positive regulator of stress responses in Arabidopsis.
AB - AtSAP5, one of approximately 14 members of the Stress Associated Protein gene family in Arabidopsis, was identified by its expression in response to salinity, osmotic, drought and cold stress. AtSAP5 shows strong homology to OSISAP1, an A20/AN1-type zinc finger protein implicated in stress tolerance in rice. To evaluate the function of AtSAP5 in the regulation of abiotic stress responses, transgenic Arabidopsis plants that over-express AtSAP5 (35S::AtSAP5) were characterized, along with wild-type and T-DNA knock-down plants. Plants that over-express AtSAP5 showed increased tolerance to environmental challenges including salt stress, osmotic stress and water deficit. Comparison of gene expression patterns between 35S::AtSAP5 transgenic plants and wild-type plants under normal conditions and water deficit stress indicated that over-expression of AtSAP5 correlates with up-regulation of drought stress responsive gene expression. Analysis of transgenic plants that express GFP-AtSAP5 showed that it is localized primarily in nuclei of root cells and recombinant AtSAP5 has E3 ubiquitin ligase activity in vitro. These results indicate that AtSAP5 has E3 ligase activity and acts as a positive regulator of stress responses in Arabidopsis.
KW - A20/AN1 zinc finger protein
KW - Abiotic stress
KW - AtSAP5
KW - E3 ubiquitin ligase
UR - http://www.scopus.com/inward/record.url?scp=79952036936&partnerID=8YFLogxK
U2 - 10.1007/s11103-011-9748-2
DO - 10.1007/s11103-011-9748-2
M3 - Article
C2 - 21293909
AN - SCOPUS:79952036936
SN - 0167-4412
VL - 75
SP - 451
EP - 466
JO - Plant molecular biology
JF - Plant molecular biology
IS - 4-5
ER -