Cell Biology Laboratory -- Investigating Lysosomal Trafficking

Dr. Editte Gharakhanian, Principal Investigator

Contact: eghara@csulb.edu

 Welcome to our website! We find the field of trafficking just fascinating. How do cells know what cargo to take to different organelles? What are the proteins responsible for delivering specific proteins to specific locations in the cell? These are interesting questions of cell biology. Furthermore, when the trafficking of cargo breaks down in cells, it leads to different diseases.

 In our laboratory, we use the latest cell and molecular approaches to dissect the cellular machinery involved in trafficking of cargo to the lysosome. The lysosome is the degradative organelle of the cell. As such, it is responsible for degrading internalized toxins and toxic cellular byproducts, old organelles, and unwanted macromolecules. It is also responsible for the maintenance of pH and ion homeostasis. To carry these functions correctly, cells must not only deliver the components that need to be degraded, but they also need to deliver the enzymes responsible for their degradation. Therefore, trafficking of cargo and enzymes to the lysosome is tightly regulated. Defects in trafficking and lysosomal function are associated with deadly and debilitating diseases. These include a class of diseases called lysosomal storage diseases which include Tay Sachs. The ability of cancer cells to metastasize and invade other tissues is also linked to correct lysosomal trafficking. Most recently, correct lysosomal trafficking and function have been linked to different neurodegenerative diseases including Alzheimer's Disease.

 

We use the elegant model system of baker's yeast, Saccharomyces cerevisiae, to identify proteins involved in the final stage of trafficking to the lysosome. We have used a novel screen to identify mutants defective in lysosomal function and morphology. You can see how our mutants are different from normal cells in the pictures. We are in the process of cloning the defective genes and identifying their roles in lysosomal trafficking.

 We have several undergraduates and masters students in our lab working hard to find answers. We learn a lot together, not just about science, but about working as a team, not giving up, and believing in ourselves. Come and check us out in MLSC, and join us!!