Identification and characterization of the pseudorabies virus UL43 protein.
Among the least characterized herpesvirus membrane proteins are the homologs of UL43 of herpes simplex virus 1 (HSV-1). To identify and characterize the UL43 protein of pseudorabies virus (PrV), part of the open reading frame was expressed in Escherichia coli and used for immunization of a rabbit. The antiserum recognized in Western blots a 34-kDa protein in lysates of PrV infected cells and purified virions, demonstrating that the UL43 protein is a virion component. In indirect immunofluorescence analysis, the antiserum labeled vesicular structures in PrV infected cells which also contained glycoprotein B. To functionally analyze UL43, a deletion mutant was constructed lacking amino acids 23-332 of the 373aa protein. This mutant was only slightly impaired in replication as assayed by one-step growth kinetics, measurement of plaque sizes, and electron microscopy. Interestingly, the PrV UL43 protein was able to inhibit fusion induced by PrV glycoproteins in a transient expression-fusion assay to a similar extent as gM. Double mutant viruses lacking, in addition to UL43, the multiply membrane spanning glycoproteins K or M did not show a phenotype beyond that observed in the gK and gM single deletion mutants.
Klupp
Barbara G
BG
Friedrich-Loeffler-Institut, Institute of Molecular Biology, Boddenblick 5A, 17493 Greifswald-Insel Riems, Germany.
Altenschmidt
Jan
J
Granzow
Harald
H
Fuchs
Walter
W
Mettenleiter
Thomas C
TC
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D017353:Gene Deletion; D011558:Herpesvirus 1, Suid / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D008561:Membrane Fusion / Q000187:drug effects; D008969:Molecular Sequence Data; D009154:Mutation; D011817:Rabbits; D014162:Transfection; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D014771:Virion / Q000378:metabolism*
D014759:Viral Envelope Proteins