Evolutionary Analysis Reveals a Single Amino Acid in the AAV Entry Receptor (AAVR) of Cats That Disrupts Binding of a Major Phylogenetic Group of AAVs.

Adeno-associated virus (AAV) is a small ssDNA satellite virus that receives wide attention due to its popularity as a safe and effective gene therapy vector. The AAV cell entry receptor (AAVR) for most serotypes is a glycoprotein containing five polycystic kidney disease (PKD) domains with which AAV interacts. AAV serotypes can be classified into three groups: those that interact primarily with PKD1, those whose interactions with PKD2 are stronger, and AAV4-like serotypes whose transduction is AAVR-independent. A phylogenetic analysis of AAVR and paralog KIAA0319 revealed AAVR amino acid variability in the region of PKD1 that is bound by AAV. We hypothesized that the substitution, in all cat-like animals, of a glutamate at a site that is an arginine (R353) in human AAVR may interfere with the binding of clade H AAVs that interact exclusively with PKD1. Analysis of PKD1 mutations, including ELISA, shows that an R353E substitution of glutamate for arginine affects the binding of the clade H AAVs that interact primarily with PKD1.