Structure of Rack1A
August 7, 2012. An interesting seminar on, “Small Compounds Regulate Scaffold Protein RACK1A Mediated Cellular Stress Signaling Pathways in Arabidopsis and rice” was delivered by Dr. Hemayet Ullah, Associate Professor, Biology, Dept. at Howad University on Monday, the 6th of August at 11 a.m. in KAL gallery at the Department of Biochemistry and Molecular Biology, DU. The talk focused on RACK1 (Receptor for Activated C Kinase 1) proteins of plants which are WD-40 type scaffold protein, conserved in eukaryotes. Model plant Arabidopsis thaliana genome maintains three different RACK1 genes termed RACK1A, RACK1B, and RACK1C with a very high (85-93%) sequence identity among themselves. Loss of function mutants inArabidopsis indicates that RACK1 proteins regulate diverse environmental stress signaling pathways including drought stress resistance pathway. Crystal structure of Arabidopsis Rack1A indicates that it can potentially be regulated by post-translational modifications, like tyrosine phosphorylations and sumoylation at key residues. On this note small inhibitor molecules were searched that can target these residues in Rack1 and inhibit the phosphorylation or sumoylation activity. These molecules thus can help a plant to survive under drought and salt stress. The important note is these compound can be used as fertilizer during environmental stress to help plants coping the stress. The group is currently working on Arabidopsis and rice as a trial. [Summarized by a Ph.D. student Ms Sabrina Elias]