University of Kentucky
Defining Domains of a Replication Protein in Tombusviridae Essential for Viral Replication Organelle Formation
Grade Level at Time of Presentation
Junior
Major
Agricultural and Medical Biotechnology
KY House District #
85
KY Senate District #
15
Faculty Advisor/ Mentor
Peter Nagy, PhD.
Department
Dept. of Plant Pathology
Abstract
Tombusviridae is a family of positive sense, single-stranded RNA viruses that infect a wide variety of vegetation, including food sources such as tomato and cucumber plants. Due to the relatively small genomes of these viruses, a master regulatory protein (p33) recruits a plethora of co-opted host factors to form viral replication organelles (VROs). The VROs are considered viral-induced membranous organelles, which protect the viral replication complexes (VRCs) from host RNases. The formation of VROs depletes the cell of resources essential for vital metabolic processes. Exhausting cells can lead to leaf mottling and eventually result in plant death. As the global population continues to grow, the demand for food will increase. Investigating the interaction between p33 and host factors will provide information necessary to develop targeted antiviral agents. These agents will aid in decreasing cell exhaustion and increase the yield of crops necessary to feed a demanding population. This project focuses specifically on the interaction between p33 and peroxisomes. The transmembrane domains of p33 insert into the membranes of peroxisomes; causing a series of events leading to an irregular aggregation of said organelles within the cytosol. Directed deletions of different domains of p33 can help determine which specific amino acid sequences are necessary for co-opted recruitment of peroxisomes. It is anticipated that any deletion in the ORF gene (ORF encodes the master regulator) that results in knocking out amino acid sequences located in either of the transmembrane domains of p33 will result in failed VRO formation. Much previous literature has confirmed the necessary dimerization of p33 proteins. Thus, introducing a mutant p33 (incapable of forming VROs) to cells infected with a virus within the family of Tombusviridae may prevent wildtype master regulators from aggregating peroxisomes in the cytosol. Without the formation of VROs, progeny viral RNA cannot be synthesized.
Defining Domains of a Replication Protein in Tombusviridae Essential for Viral Replication Organelle Formation
Tombusviridae is a family of positive sense, single-stranded RNA viruses that infect a wide variety of vegetation, including food sources such as tomato and cucumber plants. Due to the relatively small genomes of these viruses, a master regulatory protein (p33) recruits a plethora of co-opted host factors to form viral replication organelles (VROs). The VROs are considered viral-induced membranous organelles, which protect the viral replication complexes (VRCs) from host RNases. The formation of VROs depletes the cell of resources essential for vital metabolic processes. Exhausting cells can lead to leaf mottling and eventually result in plant death. As the global population continues to grow, the demand for food will increase. Investigating the interaction between p33 and host factors will provide information necessary to develop targeted antiviral agents. These agents will aid in decreasing cell exhaustion and increase the yield of crops necessary to feed a demanding population. This project focuses specifically on the interaction between p33 and peroxisomes. The transmembrane domains of p33 insert into the membranes of peroxisomes; causing a series of events leading to an irregular aggregation of said organelles within the cytosol. Directed deletions of different domains of p33 can help determine which specific amino acid sequences are necessary for co-opted recruitment of peroxisomes. It is anticipated that any deletion in the ORF gene (ORF encodes the master regulator) that results in knocking out amino acid sequences located in either of the transmembrane domains of p33 will result in failed VRO formation. Much previous literature has confirmed the necessary dimerization of p33 proteins. Thus, introducing a mutant p33 (incapable of forming VROs) to cells infected with a virus within the family of Tombusviridae may prevent wildtype master regulators from aggregating peroxisomes in the cytosol. Without the formation of VROs, progeny viral RNA cannot be synthesized.