Prateek Jain
National Agri Food Biotechnology Institute, India
Title: Role of interacting B-ZIP transcription factors in Arabidopsis thaliana seed development: Use of a designed dominant negative protein
Biography
Biography: Prateek Jain
Abstract
The B-ZIP motif is a long bipartite α-helix. The C-terminal half is responsible for dimerization whereas N-terminal binds to sequence-specific DNA. The N-terminal basic region is unstructured in the absence of DNA but forms an alpha-helix when bound to DNA. We have replaced the basic N-terminal domain with a rationally designed acidic extension. Dimerization specificity of BZIP10, BZIP25 and BZIP53 with each other and with our designed dominant negative A-ZIP53 and its mutants was evaluated using biochemical and biophysical assays. The acidic extension act as a DNA template and extends the alpha-helical coiled coil to N-terminal. This acidic extension heterodimerize with wild type basic region and inhibit the DNA binding activities of wild type proteins. Circular dichroism results indicate that heterodimer of designed acidic leucine zipper and basic leucine zipper is more stable than homodimer of wild type B-ZIPs. Gel shift experiments showed the inhibition of wild type BZIP53, BZIP25 and BZIP10 by A-ZIP53 in equimolar concentrations. Transient transfections studies using Arabidopsis protoplast proved the in vivo efficacies of these dominant negative proteins. Unlike siRNA and other knockout technology our designed dominant negative heterodimerizes with all the memebers of same B-ZIP families thus overcoming the problem of biological redundancy.