Multiple interactions control the intracellular localization of the herpes simplex virus type 1 capsid proteins.
Herpes simplex virus type 1 (HSV-1) capsid assembly takes place in the nucleus of infected cells. However, when each of the outer capsid shell proteins, VP5, VP23 and VP26, is expressed in the absence of any other HSV-1 proteins, it does not localize to the nucleus but is distributed throughout the cell. We have previously shown that the HSV-1 capsid scaffolding protein, preVP22a, can relocate VP5 into the nucleus but does not influence the distribution of VP23. We now demonstrate that the outer capsid shell protein, VP19C, is able to relocate both VP5 and VP23 separately into the nucleus. However, nuclear localization of VP26 is only observed when VP5 is present together with either VP19C or preVP22a. Thus, pair-wise interactions involving all of the abundant capsid proteins have now been identified. Electron microscope examination of insect cells coinfected with recombinant baculoviruses expressing VP19C and VP5 reveals the presence of 70 nm diameter 'capsid-like' structures, suggesting that these two proteins can form the basic capsid shell.
Rixon
F J
FJ
Medical Research Council Virology Unit, Institute of Virology, Glasgow, UK. F.rixon@vir.gla.ac.uk
Addison
C
C
McGregor
A
A
Macnab
S J
SJ
Nicholson
P
P
Preston
V G
VG
Tatman
J D
JD
D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics / Q000648:ultrastructure; D001483:Base Sequence; D001692:Biological Transport; D002213:Capsid / Q000235:genetics / Q000378:metabolism*; D036022:Capsid Proteins; D002460:Cell Line; D006224:Cricetinae; D004279:DNA, Viral; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera / Q000166:cytology
D036022:Capsid Proteins; D004279:DNA, Viral; D011993:Recombinant Fusion Proteins; C082563:VP19 protein, Human herpesvirus 1; C079750:VP23 protein, Human herpesvirus 1; C442523:VP5 protein, Herpes simplex virus type 1; C077409:capsid protein VP26, herpes simplex virus type 1