Novel Coxsackievirus and Adenovirus Receptor Interacting Partners

Abstract

<p>The Coxsackievirus and adenovirus receptor (CAR) is both a cell adhesion molecule and a viral receptor. The gene encoding human CAR, CXADR, consists of 8 alternatively spliced exons terminating in either exon 7 (CAREx7) or exon 8 (CAREx8). Both splice forms differ only in the last 26 (exon 7, -GSIV) or 13 (exon 8, -ITVV) amino acids. Both isoforms behave as viral receptors, however, in polarized epithelial cells, in contrast to the basolateral localization of CAREx7, CAREx8 localizes to the apical surface where it may act as a viral receptor. We hypothesized that apical localization of the human CAREx8 isoform is due to interactions with cellular proteins within the apical sorting pathway. In order to identify putative interacting partners of CAREx8, a yeast two hybrid (Y2H) assay was performed (Clontech Matchmaker Gold Yeast Two-Hybrid System). The entire C-terminus of human CAREx8 was cloned into an expression vector that served as bait in the assay. A cDNA library from well differentiated primary human bronchial epithelial cells was generated and inserted into another expression vector which served as the prey. The mating between yeast carrying either the bait or prey resulted in a number of colonies able to survive on double dropout or quadruple dropout plates. The two most frequently identified genes/proteins interacting with CAREx8 were guanine nucleotide binding protein-like 2 (GNL2) and coiled-coil domaincontaining protein 14 (CCDC14). Both putative candidate proteins are implicated in cellular trafficking. Further characterization of the interactions between these proteins with CAREx8 is underway. The identification and characterization of cellular interactions with CAREx8 will improve our understanding of the mechanism behind the apical expression and localization of CAREx8 and may lead to new ways to alter viral susceptibility.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 8, 2011</p>