IP: Lynne Yenush y JM Mulet
IP: JM Mulet
IP: Lynne Yenush y JM Mulet
GENERAL DESCRIPTION OF SCIENTIFIC INTERESTS:
Ion homeostasis is a dynamic process and a fundamental requirement for all organisms. Many different minerals are required for essential biochemical processes, but accumulation of these elements is toxic. Thus, all living organisms have developed efficient systems to acquire and store these elements and robust mechanisms to maintain homeostatic concentrations to avoid toxicity and to respond to environmental changes.
Potassium is a key monovalent cation necessary for multiple aspects of cell growth and survival, for example compensation of negative charges of macromolecules, maintenance of electroneutrality, cell turgor and volume, enzyme activity, protein synthesis, and maintenance of proper membrane potential and intracellular pH. The long term, general goal of our research group is to generate new knowledge regarding the regulation of potassium transporters from both plants and yeast which may be applied in future in biotechnological approaches to improve plant drought tolerance and industrial performance of yeast.
In plants, apart from the basic, general physiological functions listed above for potassium at the cellular level, this cation also plays a key role at the whole plant level, as it is involved in important processes such as stomatal aperture that controls transpirational water loss and plant desiccation. Inward rectifying channels (Kin) are responsible for potassium influx into guard cells and play a key role in stomatal opening. KAT1, and its close homologue KAT2, are the main inward rectifying channels expressed in guard cells. Our current project is focused on the characterization 14 proteins that we have identified in a Split-Ubiquitin protein-protein interaction screen searching for KAT1 potassium channel interactors from the model plant Arabidopsis thaliana.
We are taking several biochemical and genetic approaches to confirm these interactors and their effect on KAT1 activity in plants. The identification of physiologically relevant regulators of K+ channels will aid in the design of approaches that may impact both drought tolerance and pathogen susceptibility, since these pores are responsible for CO2 uptake and transpirational water loss and are the point of entry for certain pathogens.
In addition we are interested in studying the regulation of the high affinity potassium transporter of yeast, Trk1. The regulation of this transporter is crucial for the regulation of nutrient uptake and, recently, a direct effect of both external and internal potassium and pH on ethanol tolerance in conditions relevant for the industrial production of bioethanol has been reported. In addition, several studies clearly indicate that the proteins involved in determining and maintaining plasma membrane potential through the modulation of potassium homeostasis represent promising targets for complimentary antifungal treatments. Therefore, the identification of proteins that regulate the activity of this potassium transporter has potential applications in both agronomic, industrial and medical contexts.