title: The AAA-ATPase NVL2 is a component of pre-ribosomal particles that interacts with the DExD/H-box RNA helicase DOB1.
abstract: Nuclear VCP/p97-like protein 2 (NVL2) is a member of the chaperone-like AAA-ATPase family with two conserved ATP-binding modules. Our previous studies have shown that NVL2 is localized to the nucleolus by interacting with ribosomal protein L5 and may participate in ribosome synthesis, a process involving various non-ribosomal factors including chaperones and RNA helicases. Here, we show that NVL2 is associated with pre-ribosomal particles in the nucleus. Moreover, we used yeast two-hybrid and co-immunoprecipitation assays to identify an NVL2-interacting protein that could yield insights into NVL2 function in ribosome biogenesis. We found that NVL2 interacts with DOB1, a DExD/H-box RNA helicase, whose yeast homologue functions in a late stage of the 60S subunit synthesis. DOB1 can interact with a second ATP-binding module mutant of NVL2, which shows a dominant negative effect on ribosome synthesis. In contrast, it cannot interact with a first ATP-binding module mutant, which does not show the dominant negative effect. When the dominant negative mutant of NVL2 was overexpressed in cells, DOB1 appeared to remain associated with nuclear pre-ribosomal particles. Such accumulation was not observed upon overexpression of wild-type NVL2 or a nondominant-negative mutant. Taken together, our results suggest that NVL2 might regulate the association/dissociation reaction of DOB1 with pre-ribosomal particles by acting as a molecular chaperone.
authors.affiliation: School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan. nagahama@bio.tokushima-u.ac.jp
authors.forename: Masami
authors.initials: M
authors.lastname: Nagahama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamazoe
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Hara
authors.forename: Katsuko
authors.initials: K
authors.lastname: Tani
authors.forename: Akihiko
authors.initials: A
authors.lastname: Tsuji
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Tagaya
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism*
chemical_list: D000251:Adenosine Triphosphatases; C512513:MTREX protein, human; D000074183:ATPases Associated with Diverse Cellular Activities; C500249:NVL protein, human; D020365:RNA Helicases