AAA+ proteins RUVBL1 and RUVBL2 coordinate PIKK activity and function in nonsense-mediated mRNA decay.
Phosphatidylinositol 3-kinase-related protein kinase (PIKK) family proteins play essential roles in DNA-based and RNA-based processes, such as the response to DNA damage, messenger RNA (mRNA) quality control, transcription, and translation, where they contribute to the maintenance of genome integrity and accurate gene expression. The adenosine triphosphatases associated with diverse cellular activities (AAA+) family proteins RuvB-like 1 (RUVBL1) and RUVBL2 are involved in various cellular processes, including transcription, RNA modification, DNA repair, and telomere maintenance. We show that RUVBL1 and RUVBL2 associate with each PIKK family member. We also show that RUVBL1 and RUVBL2 control PIKK abundance at least at the mRNA level. Knockdown of RUVBL1 or RUVBL2 decreased PIKK abundance and impaired PIKK-mediated signaling. Analysis of SMG-1, a PIKK family member involved in nonsense-mediated mRNA decay (NMD), revealed an essential role for RUVBL1 and RUVBL2 in NMD. RUVBL1 and RUVBL2 associated with SMG-1 and the messenger ribonucleoproteins in the cytoplasm and promoted the formation of mRNA surveillance complexes during NMD. Thus, RUVBL1 and RUVBL2 regulate PIKK functions on two different levels: They control the abundance of PIKKs, and they stimulate the formation of PIKK-containing molecular complexes, such as those involved in NMD.
Izumi
Natsuko
N
Department of Molecular Biology, Yokohama City University School of Medicine, Yokohama, Japan.
Yamashita
Akio
A
Iwamatsu
Akihiro
A
Kurata
Rie
R
Nakamura
Hiroki
H
Saari
Bonnie
B
Hirano
Hisashi
H
Anderson
Philip
P
Ohno
Shigeo
S
D000074183:ATPases Associated with Diverse Cellular Activities; D000818:Animals; D015153:Blotting, Western; D017173:Caenorhabditis elegans; D002352:Carrier Proteins / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli; D006801:Humans; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D016297:Mutagenesis, Site-Directed; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D020871:RNA Stability / Q000235:genetics / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000378:metabolism
D000074183:ATPases Associated with Diverse Cellular Activities; D002352:Carrier Proteins; D004265:DNA Helicases; D018076:DNA, Complementary; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D034741:RNA, Small Interfering; D012261:Ribonucleoproteins; C514704:SMG1 protein, human; C486549:RUVBL1 protein, human; C122079:RUVBL2 protein, human