Faculty Sponsor: Davidson Biology Department – Bryan Thurtle-Schmidt
Cells maintain homeostasis by importing necessary materials for viability and excreting waste in order to function ideally. Boron is an essential micronutrient that is used for optimal growth in plants but is toxic in excess. The boron efflux transporter, Bor3, a membrane transport protein, is a part of the solute carrier 4 family (SLC4) and regulates borate concentrations by degrading in response to high accumulation in the shoots to save the plant. By using Saccharomyces cerevisiae Bor1 as a model, comparisons were made of both transporters through homologous proteins to identify significant amino acids along the dimerization interface. Site-directed mutagenesis was utilized to mutate amino acids along the interface to alanines, smaller amino acids, in hopes to prevent dimerization. This was all done to better understand the mechanisms of the dimer in the gate domain. Mutant amino acids were then tested on boric acid plates in a yeast genetic complementation assay in order to test whether or not the dimerization was disrupted. The results suggest that the single mutants containing the W and V primers displayed a null phenotype inferring that it plays a negative role in dimerization.