Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0268318 (ICP)
 10,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In cells infected with herpes simplex virus, HSV-I, newly synthesized polypeptides accumulated in the nucleus at different rates, which did not change during the first 6 h after infection. Canavanine, an arginine analogue, prevented the nuclear accumulation of ICP (infected cell polypeptides) 5 and 8 and azetidine, a proline analogue, prevented that of ICP 5 and 7. The transfer of polypeptides to the nucleus was inhibited at 4 degrees C but not by dinitrophenol. Some of the nuclear polypeptides could be released by washing isolated nuclei with hypertonic salt solutions. ICP 17 was particularly sensitive to high salt treatment while ICP 5 and II were resistent. ICP 4b, a modified form of the alpha polypeptide ICP 4, was released by EDTA, and the detergent NP40 removed ICP II. Treatment of nuclei with DNase selectively reduced the amount of bound alpha polypeptides ICP 4c (the second modified form of ICP 4), 0 and 27 as well as ICP 8 and 25. Nuclei isolated from infected or uninfected cells and incubated in labelled cytoplasmic extracts took up primarily ICP 8 and 32. Alpha polypeptides were taken up to a lesser extent and ICP 6 and 10 were excluded. It is concluded that affinities for various constituents of host cell nuclei are likely to determine the nuclear accumulation of specific virus polypeptides.
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PMID:On the association of virus proteins with the nuclei of cells infected with herpes simplex virus. 20 19

The localization of ICP 4, ICP 8, DNA polymerase and alkaline exonuclease within herpes simplex virus type 1 (HSV)-infected cells has been examined by immunofluorescence using specific antibodies to these proteins. Cells were simultaneously counterstained with the DNA-binding fluorochrome 4,6-diamidino-2-phenylindole (DAPI) to reveal the intranuclear distribution of DNA. These studies showed that in the absence of virus DNA replication ICP 4, ICP 8 and DNA polymerase were diffusely distributed throughout the nucleus but during virus DNA replication these proteins accumulated at specific foci within the nucleus. Initially these foci were near the nuclear membrane but with continuing virus DNA replication they increased in size until the whole of the nucleus became affected. The increase in size of these foci was coincident with a redistribution of nuclear DNA and margination of chromatin at the nuclear membrane, as revealed by DAPI staining. The number of foci initially present in an infected cell was dependent on the multiplicity of infection. The distribution of ICP 4, ICP 8 and DNA polymerase within the nucleus was altered by treating the cells with DNase. The majority of alkaline exonuclease was diffusely distributed throughout the nucleus during virus DNA replication and did not localize at specific foci within the nucleus. Autoradiographic examination of the incorporation of [3H]thymidine in cells infected with HSV showed that viral DNA replication occurred in restricted areas within the nucleus that were similar, in terms of number, location and size, to the foci where ICP 4, ICP 8 and DNA polymerase accumulated. Furthermore, in cells blocked in mitosis following infection with HSV, ICP 4, ICP 8 and DNA polymerase, but not alkaline exonuclease, localized in areas outside the condensed chromatin structures. DAPI staining revealed the presence of DNA in these areas and, as such structures were never seen when uninfected cells had entered mitosis, it is suggested that this extrachromosomal DNA is of viral origin. These studies therefore suggest that ICP 4 is associated with progeny virus DNA and that while its intranuclear localization is initially at non-viral sites, as DNA replication proceeds so ICP 4 is recruited into areas of virus DNA transcription and replication.
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PMID:Intranuclear localization of herpes simplex virus immediate-early and delayed-early proteins: evidence that ICP 4 is associated with progeny virus DNA. 302 Jan 58