A seminar on, “Small Compounds Regulate Scaffold Protein RACK1A Mediated Cellular Stress Signaling Pathways in Arabidopsis and rice” will be 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. All interested listeners are cordially invited to attend the function.The abstract of the seminar is only a click away from the readers. Read the abstract given below:
|Abstract of the Seminar to be held on the 6th of August, 2012
Scaffold proteins are known as important cellular regulators that can interact with multiple proteins to modulate diverse signal transduction pathways. RACK1 (Receptor for Activated C Kinase 1) is a WD-40 type scaffold protein, conserved in eukaryotes, from Chlamydymonas to plants and humans, plays regulatory roles in diverse signal transduction and stress response pathways. RACK1 in humans has been implicated in myriads of neuropathological diseases including Alzheimer and alcohol addictions. 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 in Arabidopsis indicates that RACK1 proteins regulate diverse environmental stress signaling pathways including drought stress resistance pathway. Recently deduced crystal structure of Arabidopsis RACK1A- very first among all the RACK1 proteins, indicates that it can potentially be regulated by post-translational modifications, like tyrosine phosphorylations and sumoylation at key residues. Here we show evidence that RACK1A proteins, depending on diverse environmental stresses, are tyrosine phosphorylated and sumoylated. Utilizing site-directed mutagenesis of key tyrosine and lysine residues, it is found that tyrosine phosphorylation and sumoylation can potentially dictate the homo-dimerization of RACK1A proteins. Targeting the diverse post-translational modification sites of RACK1A, small inhibitor compounds are isolated that shows potential for use as anti-drought compound. High efficacy compounds are identified for their ability to counter specific environmental stress pathways known to be regulated by RACK1A protein. Considering the very high structural conservation of RACK1A across the kingdoms, similar compounds are expected to regulate human RACK1 regulated pathological conditions as well.