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Updated: Jul 5, 2026
Identification of Functional Protein Regions Through Chimeric Protein Construction
Published on: January 8, 2019
Identification of functional domains of phosphoproteins of two morbilliviruses using chimeric proteins
Paramananda Saikia1, M S Shaila
1Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Abstract:
The paramyxovirus P protein is an essential component of the transcriptase and replicase complex along with L protein. In this article, we have examined the functional roles of different domains of P proteins of two closely related morbilliviruses, Rinderpest virus (RPV) and Peste des petits ruminants virus (PPRV). The PPRV P protein physically interacts with RPV L as well as RPV N protein when expressed in transfected cells, as shown by co-immunoprecipitation. The heterologous L-P complex is biologically active when tested in a RPV minigenome replication/transcription system, only when used with PPRV N protein but not with RPV N protein. Employing chimeric PPRV/RPV cDNAs having different coding regions of P protein in the minigenome replication/transcription system, we identified a region between 290 and 346 aa in RPV P protein necessary for transcription of the minigenome.
Insights
The P protein of paramyxoviruses is crucial for replication. Researchers found a specific region (290-346 aa) in Rinderpest virus P protein essential for minigenome transcription.
Area of Science:
- Virology
- Molecular Biology
Background:
- The P protein is a key component of the paramyxovirus transcriptase and replicase complex.
- Understanding the P protein's functional domains is vital for studying morbilliviruses like Rinderpest virus (RPV) and Peste des petits ruminants virus (PPRV).
Purpose of the Study:
- To investigate the functional roles of different domains within the P proteins of RPV and PPRV.
- To identify specific regions of the P protein critical for viral transcription and replication.
Main Methods:
- Co-immunoprecipitation assays were used to examine protein interactions between PPRV P and RPV L/N proteins in transfected cells.
- A Rinderpest virus minigenome replication/transcription system was employed to test the biological activity of heterologous L-P complexes.
- Chimeric PPRV/RPV cDNAs were constructed to map functional regions within the P protein.
Main Results:
- PPRV P protein physically interacts with both RPV L and N proteins.
- The heterologous L-P complex demonstrated biological activity only when combined with PPRV N protein, not RPV N protein.
- A specific region (amino acids 290-346) in the RPV P protein was identified as essential for minigenome transcription.
Conclusions:
- The P protein's domains play distinct roles in morbillivirus replication and transcription.
- Specific interactions between P and N proteins are critical for the formation of an active transcription/replication complex.
- The identified RPV P protein region (290-346 aa) is a key determinant for minigenome transcription, offering insights into viral polymerase function.
