Publication Date


Document Type


Committee Members

Scott Baird (Committee Member), Katherine Excoffon (Advisor), Heather Hostetler (Committee Member)

Degree Name

Master of Science (MS)


In polarized epithelia, the seven exon isoform of the Coxsackievirus and adenovirus receptor (CAREx7) is a basolateral cell-cell adhesion protein that is inaccessible for viral infection. In contrast, the eight-exon CAR isoform (CAREx8) localizes at the apical surface and mediates adenovirus (AdV) infection. A PDZ-domain containing protein, MAGI-1, interacts with both isoforms of CAR. I hypothesized that each CAR isoform interacts with specific MAGI-1 PDZ domain(s). Co-immunoprecipitation, FRET and binding assays showed that CAREx7 and CAREx8 both interact with MAGI-1-PDZ3 with high affinity. CAREx8 also interacts with MAGI-1-PDZ1. Whereas the CAREx7-PDZ3 interaction regulates MAGI-1 junction localization, PDZ3 suppresses CAREx8 cell surface levels and AdV infection. Surprisingly, PDZ1 can rescue CAREx8 from MAGI-1-mediated degradation. I also hypothesized that MAGI-1 directs CAREx8 to the ER-associated degradation (ERAD) pathway. Inhibitor experiments demonstrated that ERAD-UPS is associated with MAGI-1-mediated CAREx8 degradation. These novel findings provide insight into the stability and cellular regulation of CAR.

Page Count


Department or Program

Department of Biological Sciences

Year Degree Awarded


Included in

Biology Commons