Host Pah1p phosphatidate phosphatase limits viral replication by regulating phospholipid synthesis

dc.contributor.authorZhang, Zhenluen
dc.contributor.authorHe, Guijuanen
dc.contributor.authorHan, Gil-Sooen
dc.contributor.authorZhang, Jiantaoen
dc.contributor.authorCatanzaro, Nicholasen
dc.contributor.authorDiaz, Arturoen
dc.contributor.authorWu, Zujianen
dc.contributor.authorCarman, George M.en
dc.contributor.authorXie, Lianhuien
dc.contributor.authorWang, Xiaofengen
dc.contributor.departmentBiomedical Sciences and Pathobiologyen
dc.contributor.departmentSchool of Plant and Environmental Sciencesen
dc.description.abstractReplication of positive-strand RNA viruses [(+)RNA viruses] takes place in membrane-bound viral replication complexes (VRCs). Formation of VRCs requires virus-mediated manipulation of cellular lipid synthesis. Here, we report significantly enhanced brome mosaic virus (BMV) replication and much improved cell growth in yeast cells lacking PAH1 (pah1 Delta), the sole yeast ortholog of human LIPIN genes. PAH1 encodes Pah1p (phosphatidic acid phosphohydrolase), which converts phosphatidate (PA) to diacylglycerol that is subsequently used for the synthesis of the storage lipid triacylglycerol. Inactivation of Pah1p leads to altered lipid composition, including high levels of PA, total phospholipids, ergosterol ester, and free fatty acids, as well as expansion of the nuclear membrane. In pah1 Delta cells, BMV replication protein 1a and double-stranded RNA localized to the extended nuclear membrane, there was a significant increase in the number of VRCs formed, and BMV genomic replication increased by 2-fold compared to wild-type cells. In another yeast mutant that lacks both PAH1 and DGK1 (encodes diacylglycerol kinase converting diacylglycerol to PA), which has a normal nuclear membrane but maintains similar lipid compositional changes as in pah1 Delta cells, BMV replicated as efficiently as in pah1 Delta cells, suggesting that the altered lipid composition was responsible for the enhanced BMV replication. We further showed that increased levels of total phospholipids play an important role because the enhanced BMV replication required active synthesis of phosphatidylcholine, the major membrane phospholipid. Moreover, overexpression of a phosphatidylcholine synthesis gene (CHO2) promoted BMV replication. Conversely, overexpression of PAH1 or plant PAH1 orthologs inhibited BMV replication in yeast or Nicotiana benthamiana plants. Competing with its host for limited resources, BMV inhibited host growth, which was markedly alleviated in pah1 Delta cells. Our work suggests that Pah1p promotes storage lipid synthesis and thus represses phospholipid synthesis, which in turn restricts both viral replication and cell growth during viral infection.en
dc.description.sponsorshipZZ. and GH were supported by the China Scholarship Council. Work at the GMC laboratory is supported by National Institute of Health grant GM028140. This work is partially supported by National Science Foundation grant IOS-1645740 to AD and XW. Work in the XW laboratory is also supported by the Virginia Agricultural Experiment Station and Hatch Program of National Institute of Food and Agriculture, United States Department of Agriculture. Microscopy access in Delaware Biotechnology Institute was supported by grants from the NIH-NIGMS (P20 GM103446), the NSF (IIA-1301765) and the State of Delaware. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.en
dc.format.extent29 pagesen
dc.rightsCreative Commons Attribution 4.0 Internationalen
dc.subjectbrome mosaic-virusen
dc.subjectstrand rna virusen
dc.subjectyeast saccharomyces-cerevisiaeen
dc.subjectnuclear-membrane growthen
dc.subjectprotein 1aen
dc.subjectmovement proteinen
dc.titleHost Pah1p phosphatidate phosphatase limits viral replication by regulating phospholipid synthesisen
dc.title.serialPLOS Pathogensen
dc.typeArticle - Refereeden


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