Utilizing Homology Models and Biochemical Analysis to Determine the Structural Consequences of SLC26 Anion Transport Membrane Protein Mutations

The availability of the crystal structure of a bacterial member of the SLC26 anion transporters has allowed us to create 3-dimensional models of 10 human members of this family using threading algorithms. A plethora of human diseases are associated with mutations in the genes encoding human SLC26 transporters. My project focused on localizing point mutations in the 3-D structures of the respective SLC26A2, A3 and A4. Most mutations are predicted to cause folding defects resulting in defective trafficking of the membrane protein to the cell surface. However, a number of mutations that localize to the anion-binding site may directly affect transport function. A characterization of a panel of mutants in A2 and A3 was conducted and a range of effects on cell surface expression levels were observed. In addition, a role for N-glycosylation in the cell surface stability of SLC26A2 and in the retention of certain mutants intracellularly was discovered.M.Sc