Download Mutation analysis of a recombinant NS replicon shows that influenza

Influenza A virus NEP protein antagonizes type-I interferon response and
interacts with mitochondria ATP synthase to promote viral egression
A 型流感病毒 NEP 的蛋白質體學與粒線體 ATP 合成酶在
細胞凋亡及病毒 RNA 包裝機制的功能性探討
Advisor: 王憲威 老師
Student: 潘妍如
Abstract:
Influenza A viruses contain 8 segmented RNA genomes of negative polarity and the
8 segment directs the synthesis of a collinear mRNA encoding for the non-structural
protein 1 (NS1) and a spliced mRNA product encoding for the NEP protein. These
th
proteins contribute to effective viral replication and spread, and thus are critical
virulent factors of many attentions. NS1 is largely known as a multi-regulatory factor
capable of promoting viral RNA replication and antagonizing the host innate IFN
response, while NEP pertains to assisting nucleo-cytoplasmic transport of viral RNPs
and can be found as a minor structural protein in the virion. Recent evidence further
demonstrates that NS1 negatively regulates NEP production through inhibition of
alternative splicing of the NS1 mRNA; however, it is unclear how these proteins
regulate viral virulence spatiotemporally. To identify the cellular proteins that may
participate in NEP mediated activities, we have investigated the NEP proteome by a
Tandem Affinity Tag Purification based proteomic approach and identified 20 possible
NEP interacting cellular partners that may have functional relevance in RNP
trafficking, Pol-II transcriptional control, Janus kinase signaling, and the mitochondria
ATP homeostasis. We report here that NEP interacts with mitochondria ATPsynthase
F1 subunits α and β, which may have functional importance promoting viral egression
and regulating cellular apoptosis. The interaction of NEP and ATPsynthase 5A1 was
confirmed by co-immunoprecipitation assay and in purified mitochondria, which was
further supported by a confocal imaging. In addition, we found that NEP antagonizes
type 1 interferon response and may be relevant to its binding to a JAK binding protein.
Our results may reveal the importance of NEP as a multifunctional virulent factor to
facilitate IAV egression and induced pathogenesis.