title: Cbl E3 Ligase Mediates the Removal of Nectin-1 from the Surface of Herpes Simplex Virus 1-Infected Cells.
abstract: The Cbl E3 ligase has been linked to the down-modulation of surface signaling responses by inducing internalization of surface receptors. The adaptor protein CIN85 is a partner of Cbl that augments many of these interactions. Previously, an interaction was demonstrated between ICP0 and CIN85, which results in the removal of epidermal growth factor receptor (EGFR) from the surface of the infected cells with a concomitant attenuation of EGFR signaling. Here, we examined whether Cbl mediates the removal of the herpes simplex virus 1 (HSV-1) entry receptor Nectin-1 from the surface of infected cells. We found the following: (i) that Cbl, Nectin-1, and the viral glycoprotein D (gD) form a complex in infected cells; (ii) that during infection Nectin-1 is removed from the surface of the infected cells but is retained on the surface of cells that have been depleted of Cbl; and (iii) that in cells infected with a ΔICP0 mutant virus, Nectin-1 remained on the cell surface. Thus, Cbl is necessary but not sufficient for the removal of Nectin-1 from the cell surface. In addition, we observed that in Cbl-depleted cells there was enhanced entry after infection. These cells were susceptible to secondary infections by HSV-1. Viral entry in CIN85-depleted cells was only moderately enhanced compared to that in the Cbl-depleted cells, suggesting that the Cbl-Nectin-1 interaction is likely the key to the downregulation of surface Nectin-1. The removal of the HSV-1 entry receptor Nectin-1 from the surface of the infected cells may be part of the strategy of the virus to efficiently spread to uninfected cells.IMPORTANCEThe Cbl E3 ligase suppresses surface signaling responses by inducing internalization of surface components. The targets of Cbl include such components as immune system receptors, growth factor receptors, adhesion, and cell-to-cell contact molecules. The immediate early protein ICP0 of herpes simplex virus 1 (HSV-1) interacts with CIN85, an adaptor protein that augments Cbl functions. The consequence of this interaction is the removal of the epidermal growth factor receptor (EGFR) from the surface of the infected cells with concomitant suppression of the EGF ligand signaling. The viral entry receptor Nectin-1 is also internalized during HSV-1 infection in a Cbl-dependent mechanism, and that increases the opportunity of the virus to spread to uninfected cells. The diversion of the Cbl/CIN85 endocytic machinery may be a strategy utilized by the virus to alter the cell surface pattern to prevent detrimental host responses.
authors.affiliation: University of Kansas Medical Center, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Deschamps
authors.affiliation: University of Kansas Medical Center, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA.
authors.forename: Christos
authors.initials: C
authors.lastname: Dogrammatzis
authors.affiliation: Indian Institute of Science, Department of Microbiology and Cell Biology, Bangalore, India.
authors.forename: Ranajoy
authors.initials: R
authors.lastname: Mullick
authors.affiliation: University of Kansas Medical Center, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA mkalamvoki@kumc.edu.
authors.forename: Maria
authors.initials: M
authors.lastname: Kalamvoki
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D066246:ErbB Receptors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D056945:Hep G2 Cells; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000502:physiology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism; D000075983:Nectins; D050721:Proto-Oncogene Proteins c-cbl / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism; D053586:Virus Internalization
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015815:Cell Adhesion Molecules; D017874:Immediate-Early Proteins; C000619010:NECTIN1 protein, human; D000075983:Nectins; C433810:SH3KBP1 protein, human; D014759:Viral Envelope Proteins; C039447:glycoprotein D, Human herpesvirus 1; D050721:Proto-Oncogene Proteins c-cbl; D044767:Ubiquitin-Protein Ligases; C051804:Vmw110 protein, Human herpesvirus 1; D066246:ErbB Receptors; C067419:CBL protein, human
keywords: Cbl E3 ligase; HSV-1; ICP0; Nectin-1; cell surface; endocytosis