title: The cowpea RING ubiquitin ligase VuDRIP interacts with transcription factor VuDREB2A for regulating abiotic stress responses.
abstract: Cowpea (Vigna unguiculata L. Walp) is an important grain legume cultivated in drought-prone parts of the world, having higher tolerance to heat and drought than many other crops. The transcription factor, Dehydration-Responsive Element-Binding protein 2A (DREB2A), controls expression of many genes involved in osmotic and heat stress responses of plants. In Arabidopsis, DREB2A-interacting proteins (DRIPs), which function as E3 ubiquitin ligases (EC 6.3.2.19), regulate the stability of DREB2A by targeting it for proteasome-mediated degradation. In this study, we cloned the cowpea ortholog of DRIP (VuDRIP) using PCR based methods. The 1614 bp long VuDRIP mRNA encoded a protein of 433 amino acids having a C3HC4-type Really Interesting New Gene (RING) domain in the N-terminus and a C-terminal conserved region, similar to Arabidopsis DRIP1 and DRIP2. We found VuDRIP up-regulation in response to various abiotic stresses and phytohormones. Using yeast (Saccharomyces cerevisae) two-hybrid analysis, VuDRIP was identified as a VuDREB2A-interacting protein. The results indicate negative regulation of VuDREB2A by ubiquitin ligases in cowpea similar to Arabidopsis along with their other unknown roles in stress and hormone signaling pathways.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India. Electronic address: s.ayan@iitg.ernet.in.
authors.forename: Ayan
authors.initials: A
authors.lastname: Sadhukhan
authors.affiliation: Department of Life Science and Bioinformatics, Assam University, Silchar 788011, India. Electronic address: drskpanda@gmail.com.
authors.forename: Sanjib Kumar
authors.initials: SK
authors.lastname: Panda
authors.affiliation: Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India. Electronic address: ls@iitg.ernet.in.
authors.forename: Lingaraj
authors.initials: L
authors.lastname: Sahoo
mesh_terms: D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D014157:Transcription Factors / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases
keywords: Cowpea; DREB2A; DRIP; Drought; Ubiquitin ligase; Yeast two-hybrid