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Actions of pokeweed antiviral protein on virus-infected protoplasts.
- Source :
-
Bioscience, biotechnology, and biochemistry [Biosci Biotechnol Biochem] 1997 Jun; Vol. 61 (6), pp. 994-7. - Publication Year :
- 1997
-
Abstract
- Pokeweed antiviral protein (PAP) belongs to a group of ribosome-inactivating proteins (RIPs) that inactivate ribosomes by depurinating rRNA at a specific site. To study the mechanism for the antiviral activity of PAP, the actions of PAP on TMV-infected and uninfected tobacco protoplasts were investigated. The addition of 0.33 microM PAP to TMV-inoculated protoplasts caused a complete inhibition of TMV production. The same concentration of PAP was found to inhibit protein synthesis in the virus-infected protoplasts and to kill the cells, but it had no effect on the uninfected protoplasts. The concentration dependence of protein synthesis-inhibition by PAP was related to that of inhibition of viral multiplication. Furthermore, two other RIPs (ricin A-chain and luffin-a), which showed 240 and 430-fold less activity on tobacco ribosomes than PAP in a cell-free system, did not inhibit viral multiplication even at a concentration of 3.3 microM. The analysis of RNAs from the virus-infected and PAP-treated protoplasts demonstrated that 25S rRNA was depurinated by PAP in the infected cells. These results suggest that PAP, which is normally unable to penetrate the plasma membrane of uninfected protoplasts, gains entrance to the cytosol of infected cells and prevents viral multiplication by inactivating ribosomes.
- Subjects :
- Animals
Antiviral Agents metabolism
Cell Survival drug effects
Cells, Cultured
Enzyme-Linked Immunosorbent Assay
Plant Lectins
Plant Proteins metabolism
Protoplasts cytology
Protoplasts drug effects
RNA, Ribosomal drug effects
RNA, Ribosomal genetics
Rats
Ribosome Inactivating Proteins, Type 1
Ricin pharmacology
Nicotiana ultrastructure
Tobacco Mosaic Virus metabolism
Tobacco Mosaic Virus ultrastructure
Antiviral Agents pharmacology
N-Glycosyl Hydrolases
Plant Proteins pharmacology
Plants, Toxic
Protoplasts virology
Ribosomes drug effects
Nicotiana virology
Tobacco Mosaic Virus drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0916-8451
- Volume :
- 61
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Bioscience, biotechnology, and biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 9214760
- Full Text :
- https://doi.org/10.1271/bbb.61.994