title: A role for Q/N-rich aggregation-prone regions in P-body localization.
abstract: P-bodies are cytoplasmic foci that are sites of mRNA degradation and translational repression. It is not known what causes the accumulation of RNA-degradation factors in P-bodies, although RNA is required. The yeast Lsm1-7p complex (comprising Lsm1p to Lsm7p) is recruited to P-bodies under certain stress conditions. It is required for efficient decapping and degradation of mRNAs, but not for the assembly of P-bodies. Here we show that the Lsm4p subunit and its asparagine-rich C-terminus are prone to aggregation, and that this tendency to aggregate promotes efficient accumulation of Lsm1-7p in P-bodies. The presence of glutamine- and/or asparagine-rich (Q/N-rich) regions in other P-body components suggests a more general role for aggregation-prone residues in P-body localization and assembly. This is supported by reduced P-body accumulation of Ccr4p, Pop2p and Dhh1p after deletion of these domains, and by the observed aggregation of the Q/N-rich region from Ccr4p.
authors.affiliation: Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh, UK.
authors.forename: Martin A M
authors.initials: MA
authors.lastname: Reijns
authors.forename: Ross D
authors.initials: RD
authors.lastname: Alexander
authors.forename: Michael P
authors.initials: MP
authors.lastname: Spiller
authors.forename: Jean D
authors.initials: JD
authors.lastname: Beggs
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001216:Asparagine / Q000032:analysis* / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000378:metabolism*; D005973:Glutamine / Q000032:analysis* / Q000378:metabolism; D008969:Molecular Sequence Data; D020871:RNA Stability / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism*; D017414:Ribonucleoprotein, U4-U6 Small Nuclear / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*
chemical_list: C093543:LSM4 protein, S cerevisiae; D012333:RNA, Messenger; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D005973:Glutamine; D001216:Asparagine