Online

Manuelyan, Inessa

Cellular, Molecular, and Biomedical Sciences Graduate Program

2023

Ph. D.

The Zika virus (ZIKV) epidemic of 2015 and 2016 resulted in an estimated 132 million infections, mainly in South America. Rising infections and associated neurological pathologies such as Guillain-Barré syndrome and, alarmingly, microcephaly in fetuses, prompted the World Health Organization to declare a public health emergency in 2016. Though transmission has slowed due to herd immunity, ZIKV likely continues to circulate in pockets of immunologically naïve populations, and epidemiological modeling suggests that ZIKV could re-emerge in the human population. The development of vaccines and antivirals is imperative to be prepared for another ZIKV epidemic. ZIKV is an enveloped, positive-strand RNA virus belonging to the Flavivirus genus. Its ~11kb genome encodes 10 proteins that function together, but also interact with cellular machinery, to enter cells, translate viral proteins, replicate viral RNA, assemble new viral particles, and exit from the host cell. Using affinity purification-mass spectrometry (AP-MS), we were able to approach ZIKV from two angles. A host-centric prospective compelled us to map the interaction network between host cellular proteins and viral proteins, while the virus-centric prospective led us to catalogue the post-translational modifications (PTMs) on the ZIKV proteome mediated by host cellular enzymes. With this approach, we have generated a detailed map of ZIKV-host interactions, including host-driven PTMs on ZIKV proteins. We identified novel pro- and anti-viral host factors, and discovered that host proteins are incorporated into viral particles and may influence budding efficiency. Additionally, we have uncovered phosphorylation of ZIKV proteins as a novel mechanism by which viral budding as well as cytopathicity may be regulated. The ZIKV interactome will be useful to the field for uncovering novel ways viral and host proteins interface, and may serve as starting point for the discovery therapeutic host targets. The ZIKV phosphoproteome may also facilitate the discoveries of novel viral protein functions and as well as novel mechanisms by which these functions are regulated.