Grants and Contributions:

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Title:

Mechanisms of selective host gene translation regulation in picornavirus infection

Agreement Number:

RGPIN

Agreement Value:

$170,000.00

Agreement Date:

May 10, 2017 -

Organization:

Natural Sciences and Engineering Research Council of Canada

Location:

British Columbia, CA

Reference Number:

GC-2017-Q1-02761

Agreement Type:

Grant

Report Type:

Grants and Contributions

Additional Information:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Recipient's Legal Name:

Yang, Decheng (The University of British Columbia)

Program:

Discovery Grants Program - Individual

Program Purpose:

Picornaviral infection causes global shutdown of host gene translation but still maintains essential translation of certain host genes supporting viral replication. In the search for such host cellular mRNAs, the 5’TOP (terminal oligopyrimidine tract) mRNAs are candidates of interest. The 5’TOP motif is defined by a 7-methyl-G cap followed by a C and then a stretch of 4-15 CU at the 5’ end of mRNA. The 5’TOP mRNAs (~30% of total cellular mRNAs) encode proteins of translational machinery such as ribosomal proteins and translation initiation and elongation factors. The presence of the 5’TOP motif within these mRNAs has previously been shown to cause its translation repression in conditions of cellular stress, such as starvation, radiation, and heat shock. Surprisingly, we recently found that cellular stress caused by infection of coxsackievirus B3 (CVB3), a member of picornavirus family, induced significantly enhanced expression of eukaryotic translation elongation factor 1A (eEF1A), a 5’TOP mRNA, at both the RNA and protein levels. We also found that this upregulation is parallel with increased viral protein synthesis. However, the underlying mechanism is unknown.

In this program, our Goal is to understand the relationship of selective translation of 5’TOP mRNAs and the enhanced viral infection to unravel the underlying mechanism by which CVB3 evolves to exploit the host gene expression machinery to its own benefit. We hypothesize that CVB3 infection upregulates the eEF1A expression, a 5’TOP mRNA, by epigenetic modification of gene promoter, activation of mTORC1 prosurvival signal pathway and recruiting trans-acting factor of 5’TOP motif; the upregulated eEF1A promotes CVB3 replication by specific interactions with viral RNA and proteins . We will use CVB3/eEF1A as an interaction pair for this study:

Aim 1: To elucidate the mechanism by which CVB3 infection upregulates eEF1A1 transcription.
1.1 To identify potential methylation changes of the eEF1A1 promoter which may enhance transcription.
1.2 To evaluate if upregulation of eEF1A1 transcription occurs via the mTORC1-SP1 signaling pathway.
Aim 2: To elucidate the mechanism by which CVB3 upregulates eEF1A1 translation.
2.1 To test if the first C residue at the 5’cap site enables 5’TOP mRNA binding to the cap-binding protein eEF4E.
2.2 To identify the trans-acting factors that initiate eEF1A1 5’TOP mRNA translation.
Aim 3: To determine the mechanism by which eEF1A1 promotes CVB3 replication.
3.1 To evaluate the potential interaction of eEF1A1 with CVB3 3’UTR and/or 3D RNA polymerase to support CVB3 RNA transcription.
3.2 To determine the potential interaction of eEF1A1 with CVB3 5’UTR to initiate CVB3 translation.
This program will reveal novel mechanisms by which picornavirus CVB3 subverts host machinery to promote viral replication. The results will have wide ranging impact on the fields of virology and gene regulation.