title: The Lsm1-7-Pat1 complex promotes viral RNA translation and replication by differential mechanisms.
abstract: The Lsm1-7-Pat1 complex binds to the 3' end of cellular mRNAs and promotes 3' end protection and 5'-3' decay. Interestingly, this complex also specifically binds to cis-acting regulatory sequences of viral positive-strand RNA genomes promoting their translation and subsequent recruitment from translation to replication. Yet, how the Lsm1-7-Pat1 complex regulates these two processes remains elusive. Here, we show that Lsm1-7-Pat1 complex acts differentially in these processes. By using a collection of well-characterized lsm1 mutant alleles and a system that allows the replication of Brome mosaic virus (BMV) in yeast we show that the Lsm1-7-Pat1 complex integrity is essential for both, translation and recruitment. However, the intrinsic RNA-binding ability of the complex is only required for translation. Consistent with an RNA-binding-independent function of the Lsm1-7-Pat1 complex on BMV RNA recruitment, we show that the BMV 1a protein, the sole viral protein required for recruitment, interacts with this complex in an RNA-independent manner. Together, these results support a model wherein Lsm1-7-Pat1 complex binds consecutively to BMV RNA regulatory sequences and the 1a protein to promote viral RNA translation and later recruitment out of the host translation machinery to the viral replication complexes.
authors.affiliation: Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jungfleisch
authors.affiliation: Department of Biochemistry, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland 20814-4799, USA.
authors.forename: Ashis
authors.initials: A
authors.lastname: Chowdhury
authors.affiliation: Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Alves-Rodrigues
authors.affiliation: Department of Biochemistry, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland 20814-4799, USA.
authors.forename: Sundaresan
authors.initials: S
authors.lastname: Tharun
authors.affiliation: Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
authors.forename: Juana
authors.initials: J
authors.lastname: Díez
mesh_terms: D017795:Bromovirus / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D039381:RNA Cap-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism*; D014773:Virology / Q000379:methods*; D014779:Virus Replication
chemical_list: C114069:LSM1 protein, S cerevisiae; C521832:LSM7 protein, S cerevisiae; C103266:PAT1 protein, S cerevisiae; D039381:RNA Cap-Binding Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D038621:Regulatory Sequences, Ribonucleic Acid; D029701:Saccharomyces cerevisiae Proteins; D014764:Viral Proteins
keywords: BMV; Lsm proteins; Lsm1-7; Lsm1-7-Pat1 complex; Pat1; RNA virus; decapping activators; replication; translation; viral RNA