PhD (Western Ontario)
Research areas: Virology, Molecular Biology, Biochemistry, Genetics, Transcription, Translation, and RNA structure/function
The focus of the research in our laboratory is to understand, at a molecular level, fundamental processes that are utilized by RNA viruses during their infection of host cells. To study these processes we use a messenger- or positive-sensed single-stranded (ss) RNA virus, Tomato bushy stunt virus (TBSV), as our model pathogen. This plant virus is fundamentally similar to many animal-infecting positive-sensed RNA viruses (e.g. Poliovirus, Hepatitis C virus etc.), however TBSV offers several advantages: it has a small and simple genome; studies can be performed in convenient and relatively inexpensive experimental systems; ethical concerns related to the use of animals can be avoided and; the virus is not infectious to humans or other animals.
The 4.8 kb long ssRNA genome of TBSV is directly involved in several key viral processes that are of interest to us. These include: (i) 5′ cap- & poly(A) tail-independent translation of viral proteins; (ii) replication of the viral RNA genome; and (iii) transcription of viral subgenomic (sg) mRNAs. RNA sequences and structures within the ssRNA TBSV genome are involved in each of these processes. Our research aims to: (a) determine the structure-function relationship of important RNA elements within the genome; (b) identify and characterize viral and host proteins that interact with these RNA elements and: (c) determine the molecular mechanisms by which these RNA elements and protein factors mediate the different processes. This research on the fundamental steps in the reproductive cycle of this virus will provide a better understanding of the events leading to the initiation and successful establishment of viral infections in host cells. In turn, this information will be useful for the development of effective anti-viral strategies.
Chkuaseli T, White KA. (2020) Activation of viral transcription by stepwise largescale folding of an RNA virus genome. Nucleic Acids Research 48(16):9285-9300.
Newburn LR, White KA. (2020) A trans-activator-like structure in RCNMV RNA1 evokes the origin of the trans-activator in RNA2. PLoS Pathogens 16(1):e1008271.
Gunawardene CD, Newburn LR, White KA. (2019) A 212-nt long RNA structure in the Tobacco necrosis virus-D RNA genome is resistant to Xrn degradation. Nucleic Acids Research 47(17):9329-9342
Chkuaseli T, White KA. (2018) Intragenomic Long-Distance RNA-RNA Interactions in Plus-Strand RNA Plant Viruses. Frontiers in Microbiology 9:529.
Newburn LR, White KA. (2017) Atypical RNA Elements Modulate Translational Readthrough in Tobacco Necrosis Virus D. Journal of Virology 91(8):e02443-16.
Gunawardene CD, Donaldson LW, White KA. (2017) Tombusvirus polymerase: Structure and function. Virus Research 234:74-86.
Ashton P, Wu B, D'Angelo J, Grigull J, White KA (2015) Biologically-supported structural model for a viral satellite RNA. Nucleic Acids Research 43:9965-9977.
Nicholson BL, White KA. (2014) Functional long-range RNA-RNA interactions in plus-strand RNA viruses. Nature Reviews - Microbiology 12(7):493-504.