Structural highlights
Function
[UL34_HHV11] Plays a major role in virion nuclear egress, the first step of virion release from infected cell. Viral capsids are initially assembled within the nucleus, UL31/UL34 complex induces capsids budding and envelopment into the perinuclear space. Then UL31/UL34 complex promotes fusion of perinuclear virion envelope with the outer nuclear membrane, releasing viral capsid into the cytoplasm where it will engages budding sites in the Golgi or trans-Golgi network.[1] [2] [3] [UL31_HHV11] Plays a major role in virion nuclear egress, the first step of virion release from infected cell. Viral capsids are initially assembled within the nucleus, UL31/UL34 complex induces capsids budding and envelopment into the perinuclear space. Then UL31/UL34 complex promotes fusion of perinuclear virion envelope with the outer nuclear membrane, releasing viral capsid into the cytoplasm where it will engages budding sites in the Golgi or trans-Golgi network.[4] [5]
Publication Abstract from PubMed
During nuclear egress, herpesvirus capsids bud at the inner nuclear membrane forming perinuclear viral particles that subsequently fuse with the outer nuclear membrane, releasing capsids into the cytoplasm. This unusual budding process is mediated by the nuclear egress complex (NEC) composed of two conserved viral proteins, UL31 and UL34. Earlier, we discovered that the herpesvirus nuclear egress complex (NEC) could bud synthetic membranes in vitro without the help of other proteins by forming a coat-like hexagonal scaffold inside the budding membrane. To understand the structural basis of NEC-mediated membrane budding, we determined the crystal structures of the NEC from two herpesviruses. The hexagonal lattice observed in the NEC crystals recapitulates the honeycomb coats within the budded vesicles. Perturbation of the oligomeric interfaces through mutagenesis blocks budding in vitro confirming that NEC oligomerization into a honeycomb lattice drives budding. The structure represents the first atomic-level view of an oligomeric array formed by a membrane-deforming protein, making possible the dissection of its unique budding mechanism and the design of inhibitors to block it.
Structural basis of membrane budding by the nuclear egress complex of herpesviruses.,Bigalke JM, Heldwein EE EMBO J. 2015 Dec 2;34(23):2921-36. doi: 10.15252/embj.201592359. Epub 2015 Oct, 28. PMID:26511020[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bjerke SL, Cowan JM, Kerr JK, Reynolds AE, Baines JD, Roller RJ. Effects of charged cluster mutations on the function of herpes simplex virus type 1 UL34 protein. J Virol. 2003 Jul;77(13):7601-10. PMID:12805460
- ↑ Reynolds AE, Liang L, Baines JD. Conformational changes in the nuclear lamina induced by herpes simplex virus type 1 require genes U(L)31 and U(L)34. J Virol. 2004 Jun;78(11):5564-75. PMID:15140953 doi:http://dx.doi.org/10.1128/JVI.78.11.5564-5575.2004
- ↑ Simpson-Holley M, Baines J, Roller R, Knipe DM. Herpes simplex virus 1 U(L)31 and U(L)34 gene products promote the late maturation of viral replication compartments to the nuclear periphery. J Virol. 2004 Jun;78(11):5591-600. PMID:15140956 doi:http://dx.doi.org/10.1128/JVI.78.11.5591-5600.2004
- ↑ Reynolds AE, Liang L, Baines JD. Conformational changes in the nuclear lamina induced by herpes simplex virus type 1 require genes U(L)31 and U(L)34. J Virol. 2004 Jun;78(11):5564-75. PMID:15140953 doi:http://dx.doi.org/10.1128/JVI.78.11.5564-5575.2004
- ↑ Simpson-Holley M, Baines J, Roller R, Knipe DM. Herpes simplex virus 1 U(L)31 and U(L)34 gene products promote the late maturation of viral replication compartments to the nuclear periphery. J Virol. 2004 Jun;78(11):5591-600. PMID:15140956 doi:http://dx.doi.org/10.1128/JVI.78.11.5591-5600.2004
- ↑ Bigalke JM, Heldwein EE. Structural basis of membrane budding by the nuclear egress complex of herpesviruses. EMBO J. 2015 Dec 2;34(23):2921-36. doi: 10.15252/embj.201592359. Epub 2015 Oct, 28. PMID:26511020 doi:http://dx.doi.org/10.15252/embj.201592359
