Title: How a Ca2+ regulated kinase modulate oxidative stress responses in Arabidopsis? Role of CIPK-VDAC module
Speaker: Prof. Girdhar K. Pandey. Department of Plant Molecular Biology, University of Delhi South Campus, India
Time: 3:00 pm
Date: January 13th, 2017(Friday).
Host: Dr. Ashish Srivastava
Venue: SIPPE auditorium
Calcium has been widely recognized as a key secondary messenger in mediating various plant adaptive responses. Calineurin B-like interacting protein kinases (CIPKs) are involved in diverse signaling pathways in plants by decoding calcium signals into various phosphorylation events downstream. VDAC, voltage-dependent anion channel, was identified as a novel interactor of one of the CIPKs. This CIPK physically interacts and phosphorylates C-terminus of VDAC in in vitro conditions, and Ser191 at the C-terminal of VDAC is one of the sites of phosphorylation. Co-localization and FRET experiments proved their physical interaction in the mitochondria. Analysis of loss-of-function mutants of both the genes exhibited a methyl viologen (MV) induced oxidative stress tolerant phenotype. Our analysis proved that cipk and vdac mutants accumulate less reactive oxygen species in roots under MV stress, which conclusively supports the results obtained by phenotypic analysis. Although this CIPK was previously characterized for its role in K+ nutrition signaling, our study suggests a novel role of this CIPK along with its interacting partner VDAC in regulating methyl viologen-mediated oxidative stress in Arabidopsis.
Prof. Girdhar K. Pandey received B.Sc (Hon.) in Biochemistry from Delhi University and M.Sc. in Biotechnology from Banaras Hindu University (BHU), India. He was awarded Ph.D. degree from Jawaharlal Nehru University (JNU) and then pursued post-doctoral career at the Department of Plant and Microbial Biology, University of California at Berkeley. There, he extended the work in the field of calcium mediated signaling in Arabidopsis by studying CBL-CIPK, phosphatases, channels/transporters, and transcription factors involved in abiotic stresses. Currently, he is working as Professor in the Department of Plant Molecular Biology, Delhi University South Campus.