Genetic and Functional Dissection of the Role of Individual 5-HT 2 Receptors as Entry Receptors for JC Polyomavirus.

JC polyomavirus (JCPyV) is a ubiquitous human pathogen that causes progressive multifocal leukoencephalopathy (PML). The entry receptors for JCPyV belong to the 5-hydroxytryptamine 2 receptor (5-HT ₂ R) family, but how individual members of the family function to facilitate infection is not known. We used proximity ligation assay (PLA) to determine that JCPyV interacts with each of the 5-HT ₂ receptors (5-HT ₂ Rs) in a narrow window of time during entry. We used CRISPR-Cas9 to randomly introduce stop codons in the gene for each receptor and discovered that the second intracellular loop of each was necessary for infection. This loop contains a motif possibly involved in receptor internalization by β-arrestin. Mutation of this motif and small interfering RNA (siRNA) knockdown of β-arrestin recapitulated the results of our CRISPR-Cas9 screen, showing that this motif is critical. Our results have implications for the role these receptors play in virus infection and for their normal functioning as receptors for serotonin.
(Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)