title: Tdrd3 is a novel stress granule-associated protein interacting with the Fragile-X syndrome protein FMRP.
abstract: Tudor domains are widespread among proteins involved in RNA metabolism, but only in a few cases their cellular function has been analyzed in detail. Here, we report on the characterization of the ubiquitously expressed Tudor domain containing protein Tdrd3. Apart from its Tudor domain, we show that Tdrd3 possesses an oligosaccharide/nucleotide binding fold (OB-fold) and an ubiquitin associated domain capable of binding tetra-ubiquitin. A set of biochemical experiments revealed an interaction of Tdrd3 with FMRP, the product of the gene affected in Fragile X syndrome, and its autosomal homologs FXR1 and FXR2. FMRP has been implicated in the translational regulation of target mRNAs and shown to be a component of stress granules (SG). We demonstrate that overexpression of Tdrd3 in cells induces the formation of SGs and as a result leads to its co-localization with endogenous FMRP in these structures. Interestingly, the disease-associated FMRP missense mutation I304N identified in a Fragile X patient severely impairs the interaction with Tdrd3 in biochemical experiments. We propose a contribution of Tdrd3 to FMRP-mediated translational repression and suggest that the loss of the FMRP-Tdrd3 interaction caused by the I304N mutation might contribute to the pathogenesis of Fragile X syndrome.
authors.affiliation: Department of Biochemistry, Theodor Boveri Institute, Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Bastian
authors.initials: B
authors.lastname: Linder
authors.forename: Oliver
authors.initials: O
authors.lastname: Plöttner
authors.forename: Matthias
authors.initials: M
authors.lastname: Kroiss
authors.forename: Enno
authors.initials: E
authors.lastname: Hartmann
authors.forename: Bernhard
authors.initials: B
authors.lastname: Laggerbauer
authors.forename: Gunter
authors.initials: G
authors.lastname: Meister
authors.forename: Eva
authors.initials: E
authors.lastname: Keidel
authors.forename: Utz
authors.initials: U
authors.lastname: Fischer
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D003600:Cytosol / Q000378:metabolism; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics* / Q000378:metabolism*; D005600:Fragile X Syndrome / Q000209:etiology / Q000235:genetics* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C497683:FMR1 protein, human