Characterization of the large tegument protein (ICP1/2) of herpes simplex virus type 1.
ICP1/2 (also designated VP1/2) is a 270-kDa structural protein of herpes simplex virus type 1 (HSV-1) which is located in the tegument region of the virion. In this report we describe the production of a polyclonal antiserum specific for ICP1/2 and the use of this antiserum to examine the synthesis, processing, and intracellular localization of the viral polypeptide. Pulse-labeling studies indicated that ICP1/2 is synthesized late during infection, being initially detectable between 8 and 9 hr postinfection with the rate of synthesis continuing to increase until 11 to 12 hr postinfection. Further studies on the expression of ICP1/2 in the presence or absence of viral DNA replication indicated that the synthesis of the polypeptide is absolutely dependent on viral DNA replication. These results suggest that ICP1/2 represents a gamma 2 (true late) gene product. Additionally, we have performed experiments to determine if ICP1/2 is post-translationally modified in HSV-infected cells. These studies indicated that ICP1/2 is phosphorylated on serine residues; however, we found no evidence to suggest that the protein is glycosylated. Using subcellular fractionation and indirect immunofluorescence techniques, we have determined that ICP1/2 is diffusely distributed throughout the nucleus and cytoplasm of HSV-infected cells with no specific compartmentalization of the polypeptide.
McNabb
D S
DS
Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, Shreveport 71130-3932.
Courtney
R J
RJ
D000918:Antibody Specificity; D002451:Cell Compartmentation; D002458:Cell Fractionation; D002460:Cell Line; D006031:Glycosylation; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007700:Kinetics; D010766:Phosphorylation; D018139:Simplexvirus / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D015678:Viral Structural Proteins / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*
D007106:Immune Sera; D015678:Viral Structural Proteins