Intracellular distribution of the La antigen in CV-1 cells after herpes simplex virus type 1 infection compared with the localization of U small nuclear ribonucleoprotein particles.
The La antigen is known to associate, at least transiently, with a series of small nuclear and cytoplasmic ribonucleoprotein particles (snRNPs and scRNPs), e.g. U1 and U6 snRNPs. In CV-1 cells a monoclonal antibody (MAb), directed against the La protein (La1B5), immunostained intranuclear speckles. These speckles were found to co-localize with speckles that were stained by MAbs directed against either all U snRNPs or only against U1 snRNPs. Two h after infection of CV-1 cells with herpes simplex virus type 1 (HSV-1) (strain HFEM) the staining of nuclear speckles with the anti-La MAb disappeared and the La protein was found quantitatively in the cytoplasm. In contrast nuclear speckles remained stained with the MAbs against the U snRNPs. Similar results were obtained using HSV-1 strains Lenette or 17 syn+ or temperature-sensitive (ts) mutants defective either in DNA synthesis (tsS) or in the immediate early protein (Mr 175 K) (tsK). Later in infection the La protein returned to the nucleus. Six h after infection most of the nuclear La protein was found to localize within patchy regions. These areas seem to be related to heterogeneous nuclear RNA transcription and/or processing sites, but not to DNA replication sites.
Bachmann
M
M
Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität, Mainz, F.R.G.
Falke
D
D
Schröder
H C
HC
Müller
W E
WE
D000911:Antibodies, Monoclonal / Q000276:immunology; D001324:Autoantigens / Q000032:analysis*; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis*; D003593:Cytoplasm / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D006801:Humans; D015151:Immunoblotting; D009154:Mutation; D012261:Ribonucleoproteins / Q000032:analysis*; D017411:Ribonucleoproteins, Small Nuclear; D018139:Simplexvirus / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000032:analysis; D000097585:SS-B Antigen
D000911:Antibodies, Monoclonal; D001324:Autoantigens; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D014157:Transcription Factors; D000097585:SS-B Antigen