U L 31 and U L 34 Proteins of Herpes Simplex Virus Type 1 Form a Complex That Accumulates at the Nuclear Rim and Is Required for Envelopment of Nucleocapsids
- 15 September 2001
- journal article
- research article
- Published by American Society for Microbiology in Journal of Virology
- Vol. 75 (18), 8803-8817
- https://doi.org/10.1128/jvi.75.18.8803-8817.2001
Abstract
The herpes simplex virus type 1 (HSV-1) U L 34 protein is likely a type II membrane protein that localizes within the nuclear membrane and is required for efficient envelopment of progeny virions at the nuclear envelope, whereas the U L 31 gene product of HSV-1 is a nuclear matrix-associated phosphoprotein previously shown to interact with U L 34 protein in HSV-1-infected cell lysates. For these studies, polyclonal antisera directed against purified fusion proteins containing U L 31 protein fused to glutathione- S -transferase (U L 31-GST) and U L 34 protein fused to GST (U L 34-GST) were demonstrated to specifically recognize the U L 31 and U L 34 proteins of approximately 34,000 and 30,000 Da, respectively. The U L 31 and U L 34 gene products colocalized in a smooth pattern throughout the nuclear rim of infected cells by 10 h postinfection. U L 34 protein also accumulated in pleiomorphic cytoplasmic structures at early times and associated with an altered nuclear envelope late in infection. Localization of U L 31 protein at the nuclear rim required the presence of U L 34 protein, inasmuch as cells infected with a U L 34 null mutant virus contained U L 31 protein primarily in central intranuclear domains separate from the nuclear rim, and to a lesser extent in the cytoplasm. Conversely, localization of U L 34 protein exclusively at the nuclear rim required the presence of the U L 31 gene product, inasmuch as U L 34 protein was detectable at the nuclear rim, in replication compartments, and in the cytoplasm of cells infected with a U L 31 null virus. When transiently expressed in the absence of other viral factors, U L 31 protein localized diffusely in the nucleoplasm, whereas U L 34 protein localized primarily in the cytoplasm and at the nuclear rim. In contrast, coexpression of the U L 31 and U L 34 proteins was sufficient to target both proteins exclusively to the nuclear rim. The proteins were also shown to directly interact in vitro in the absence of other viral proteins. In cells infected with a virus lacking the U S 3-encoded protein kinase, previously shown to phosphorylate the U L 34 gene product, U L 31 and U L 34 proteins colocalized in small punctate areas that accumulated on the nuclear rim. Thus, U S 3 kinase is required for even distribution of U L 31 and U L 34 proteins throughout the nuclear rim. Taken together with the similar phenotypes of the U L 31 and U L 34 deletion mutants, these data strongly suggest that the U L 31 and U L 34 proteins form a complex that accumulates at the nuclear membrane and plays an important role in nucleocapsid envelopment at the inner nuclear membrane.This publication has 38 references indexed in Scilit:
- Targeting of the mammalian nucleoporin p62 to the nuclear envelope in the yeastSaccharomyces cerevisiaeand HeLa cellsBiochemistry and Cell Biology, 1999
- NUCLEAR ASSEMBLYAnnual Review of Cell and Developmental Biology, 1997
- Signals and structural features involved in integral membrane protein targeting to the inner nuclear membrane.The Journal of cell biology, 1995
- Efficient cDNA expression vectors for stable and transient expression of HLA-DR in transfected fibroblast and lymphoid cellsHuman Immunology, 1991
- The Complete DNA Sequence of the Long Unique Region in the Genome of Herpes Simplex Virus Type 1Journal of General Virology, 1988
- The Complete DNA Sequence of Varicella-Zoster VirusJournal of General Virology, 1986
- Preparation of nuclear matrices from cultured cells: subfractionation of nuclei in situ.The Journal of cell biology, 1984
- Modifications of the Nuclear Envelope of BHK Cells After Infection with Herpes Simplex Virus Type 1Journal of General Virology, 1982
- Regulation of α genes of herpes simplex virus: Expression of chimeric genes produced by fusion of thymidine kinase with α gene promotersCell, 1981
- Characterization of Herpes Simplex Virus Strains Differing in their Effects on Social Behaviour of Infected CellsJournal of General Virology, 1968