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.
|Number of pages||11|
|State||Published - Mar 2019|
Bibliographical noteFunding Information:
We thank Dr. Julia Guez-Haddad for her valuable advice and help in bacterial expression and purification of ORF43 protein, Dr. Avi Jacobs and Dr. Irit Shoval for their assistance with confocal microscopy, Dr. Ayelet Atkins from the BIU TEM Unit, and Dr. Ilana Loinger for her advice on PCR settings. We also thank Anastasia Gelgor for her constructive advices and help. We gratefully acknowledge Prof. Jae Jung, Don Ganem, Shou Jiang Gao, Yan Yuan, Keiji Ueda and David Lukac for gifts of reagents. This work was supported by a grant from the Israel Science Foundation (Grant no. 1365/15 ).
© 2019 Elsevier Inc.
- Kaposi's sarcoma-associated herpesvirus, KSHV
- Portal protein