Ph.D. in Biochemistry and Molecular Biology with Victor Ling


Adapted a protein-fragment complementation assay (PCA) to determine interactions which exist between members of the TAP family of ½ ABC transporters.  Optimized the DHFR-PCA by cloning members of the TAP family to create DHFR protein fragment fusions with linking sequences of various lengths.  After optimization of the assay, determined that TAPL forms homodimers and does not form interactions with TAP1 or TAP2.  Furthermore, developed a method to identify false positives by detection of spontaneous mutation events in the cell line used.  This work was published in Biochemistry.


Discovered the function of TAPL.  After cloning TAPL into an insect virus, expressed TAPL in insect cells and isolated lysosomal membranes.  Then employed a transport assay with radiolabeled peptides to discover that like TAP1 and TAP2, TAPL can also transport peptides.  However, unlike the TAP transporter (made of TAP1 and TAP2) TAPL is located in lysosomal membranes, rather than in the endoplasmic reticulum.  This work was published in the Journal of Biological Chemistry, but unfortunately, not by me!  On the bright side, I can always say that my thesis was published before their paper.