Associate Professor, Howard University, Washington, DC
Heterotrimeric G-protein mediated cellular signal transduction pathway is the dominant mode of transducing extracellular signal inside the cell. Although the presence of G-protein coupled signal transduction is well documented in diverse biological systems, evidence for a comparable system in plants has just started to accumulate. By utilizing G-protein knock-out alleles in Arabidopsis, our previous works have unraveled diverse G-protein dependent signaling pathways, ranging from auxin, brassinosteroid, gibberellin, ABA, and water-stress. At present, we are interested in elucidating the cellular signal transduction pathways mediated by Receptor for Activated Kinase C (RACK1) - a structural homolog of G-protein beta subunit. Major function of RACK1 is perceived to be the integration of signals from different pathways by acting as a scaffold protein. The repertoire of non-plant RACK1 interacting proteins that contain diverse partners ranging from kinases, phosphatases, heterotrimeric G-proteins, ion channels, ribosomes, and membrane and nuclear receptors, established the protein as a multipurpose protein. Though three distinct RACK1 genes, as opposed to a single gene in non-plant organisms, are present in Arabidopsis, essentially nothing is known about their cellular functions. A combination of molecular genetic and cell biological approaches are being utilized to unravel the plant RACK1-mediated signaling pathways. Preliminary results from gene knock-out characterizations implicate RACK1 in environmental stress signaling pathways. Through structural studies, functional inhibitor compounds are isolated to use as fertilizer additive in the field to provide resistance to diverse environmental stresses. To understand the RACK1A mediated signaling mechanism, RNA-seq experiment is undertaken utilizing the functional inhibitor compounds. The results are pinpointing the cellular redox regulation pathway as the major target for mediating the resistance response.
Materials are under development.
Materials are under development.
