The KSHV portal protein ORF43 is essential for the production of infectious viral particles

Daniela Dana Dünn-Kittenplon; Inna Kalt; Jean-Paul Moshe Lellouche; Ronit Sarid

doi:10.1016/j.virol.2019.01.028

The KSHV portal protein ORF43 is essential for the production of infectious viral particles

Virology. 2019 Mar:529:205-215. doi: 10.1016/j.virol.2019.01.028. Epub 2019 Feb 1.

Authors

Daniela Dana Dünn-Kittenplon¹, Inna Kalt², Jean-Paul Moshe Lellouche³, Ronit Sarid⁴

Affiliations

¹ The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel; Department of Chemistry, Bar Ilan University, Ramat-Gan 5290002, Israel; Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan 5290002, Israel.
² The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel; Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan 5290002, Israel.
³ Department of Chemistry, Bar Ilan University, Ramat-Gan 5290002, Israel; Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan 5290002, Israel.
⁴ The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel; Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan 5290002, Israel. Electronic address: saridr@mail.biu.ac.il.

PMID: 30735904
DOI: 10.1016/j.virol.2019.01.028

Abstract

Herpesvirus capsid assembly involves cleavage and packaging of the viral genome. The Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 43 (orf43) encodes a putative portal protein. The portal complex functions as a gate through which DNA is packaged into the preformed procapsids, and is injected into the cell nucleus upon infection. The amino acid sequence of the portal proteins is conserved among herpesviruses. Here, we generated an antiserum to ORF43 and determined late expression kinetics of ORF43 along with its nuclear localization. We generated a recombinant KSHV mutant, which fails to express ORF43 (BAC16-ORF43-null). Assembled capsids were observed upon lytic induction of this virus; however, the released virions lacked viral DNA and thus could not establish infection. Ectopic expression of ORF43 rescued the ability to produce infectious particles. ORF43 antiserum and the recombinant ORF43-null virus can provide an experimental system for further studies of the portal functions and its interactions.

Keywords: Kaposi’s sarcoma-associated herpesvirus, KSHV; ORF43; Portal protein.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Capsid Proteins
DNA, Viral
Gene Expression Regulation, Viral / physiology*
Genome, Viral
HEK293 Cells
Herpesvirus 8, Human / genetics*
Herpesvirus 8, Human / metabolism*
Humans
Open Reading Frames
Viral Proteins / genetics
Virion
Virus Replication

Substances

Capsid Proteins
DNA, Viral
Viral Proteins