The C-Terminal 88 Amino Acids of the Sendai Virus P Protein Have Multiple Functions Separable by Mutation
AUTOR(ES)
Tuckis, Jeffery
FONTE
American Society for Microbiology
RESUMO
The Sendai virus P-L polymerase complex binds the NP-encapsidated nucleocapsid (NC) template through a P-NP interaction. To identify P amino acids responsible for binding we performed site-directed mutagenesis on the C-terminal 88 amino acids in the NC binding domain. The mutant P proteins expressed from plasmids were assayed for viral RNA synthesis and for various protein-protein interactions. All the mutants formed P oligomers and bound to L protein. While two mutants, JT3 and JT8, retained all P functions at or near the levels of wild-type (wt) P, three others—JT4, JT6, and JT9—were completely defective for both transcription and genome replication in vitro. Each of the inactive mutants retained significant NC binding but had a different spectrum of other binding interactions and activities, suggesting that the NC binding domain also affects the catalytic function of the polymerase. NC binding was inhibited by combinations of the inactive mutations. The remaining P mutants were active in transcription but defective in various aspects of genome replication. Some P mutants were defective in NP0 binding and abolished the reconstitution of replication from separate P-L and NP0-P complexes. In some of these cases the coexpression of the wt polymerase with the mutant NP0-P complex could rescue the defect in replication, suggesting an interaction between these complexes. For some P mutants replication occurred in vivo, but not in vitro, suggesting that the intact cell is providing an unknown function that cannot be reproduced in extracts of cells. Thus, the C-terminal region of P is complex and possesses multiple functions besides NC binding that can be separated by mutation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=135727Documentos Relacionados
- Deletion of the C-terminal 33 amino acids of cucumber mosaic virus movement protein enables a chimeric brome mosaic virus to move from cell to cell.
- Multiple C-Terminal Lysine Residues Target p53 for Ubiquitin-Proteasome-Mediated Degradation
- The C-terminal domain of p53 recognizes DNA damaged by ionizing radiation.
- Multiple Lysine Mutations in the C-Terminal Domain of p53 Interfere with MDM2-Dependent Protein Degradation and Ubiquitination
- Transformation of avian fibroblasts overexpressing the c-rel proto-oncogene and a variant of c-rel lacking 40 C-terminal amino acids.