title: The Exosome Is Recruited to RNA Substrates through Specific Adaptor Proteins.
abstract: The exosome regulates the processing, degradation, and surveillance of a plethora of RNA species. However, little is known about how the exosome recognizes and is recruited to its diverse substrates. We report the identification of adaptor proteins that recruit the exosome-associated helicase, Mtr4, to unique RNA substrates. Nop53, the yeast homolog of the tumor suppressor PICT1, targets Mtr4 to pre-ribosomal particles for exosome-mediated processing, while a second adaptor Utp18 recruits Mtr4 to cleaved rRNA fragments destined for degradation by the exosome. Both Nop53 and Utp18 contain the same consensus motif, through which they dock to the "arch" domain of Mtr4 and target it to specific substrates. These findings show that the exosome employs a general mechanism of recruitment to defined substrates and that this process is regulated through adaptor proteins.
authors: Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg 69120, Germany.
authors: Matthias
authors: M
authors: Thoms
authors: Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg 69120, Germany.
authors: Emma
authors: E
authors: Thomson
authors: Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg 69120, Germany.
authors: Jochen
authors: J
authors: Baßler
authors: Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg 69120, Germany.
authors: Marén
authors: M
authors: Gnädig
authors: Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg 69120, Germany.
authors: Sabine
authors: S
authors: Griesel
authors: Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg 69120, Germany. Electronic address: ed.hurt@bzh.uni-heidelberg.de.
authors: Ed
authors: E
authors: Hurt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001203:Ascomycota / Q000737:chemistry / Q000145:classification / Q000235:genetics; D053487:DEAD-box RNA Helicases / Q000737:chemistry / Q000378:metabolism*; D055354:Exosomes / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D012331:RNA, Fungal / Q000737:chemistry / Q000378:metabolism; D012335:RNA, Ribosomal / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: C504135:Nop53 protein, S cerevisiae; D009687:Nuclear Proteins; D012331:RNA, Fungal; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C000602833:Utp18 protein, S cerevisiae; C101004:MTR4 protein, S cerevisiae; D053487:DEAD-box RNA Helicases