Distinct argonaute-mediated 22G-RNA pathways direct genome surveillance in the C. elegans germline.
Endogenous small RNAs (endo-siRNAs) interact with Argonaute (AGO) proteins to mediate sequence-specific regulation of diverse biological processes. Here, we combine deep-sequencing and genetic approaches to explore the biogenesis and function of endo-siRNAs in C. elegans. We describe conditional alleles of the Dicer-related helicase, drh-3, that abrogate both RNA interference and the biogenesis of endo-siRNAs, called 22G-RNAs. DRH-3 is a core component of RNA-dependent RNA polymerase (RdRP) complexes essential for several distinct 22G-RNA systems. We show that, in the germline, one system is dependent on worm-specific AGOs, including WAGO-1, which localizes to germline nuage structures called P granules. WAGO-1 silences certain genes, transposons, pseudogenes, and cryptic loci. Finally, we demonstrate that components of the nonsense-mediated decay pathway function in at least one WAGO-mediated surveillance pathway. These findings broaden our understanding of the biogenesis and diversity of 22G-RNAs and suggest additional regulatory functions for small RNAs.
Gu
Weifeng
W
Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01606, USA.
Shirayama
Masaki
M
Conte
Darryl
D
Vasale
Jessica
J
Batista
Pedro J
PJ
Claycomb
Julie M
JM
Moresco
James J
JJ
Youngman
Elaine M
EM
Keys
Jennifer
J
Stoltz
Matthew J
MJ
Chen
Chun-Chieh G
CC
Chaves
Daniel A
DA
Duan
Shenghua
S
Kasschau
Kristin D
KD
Fahlgren
Noah
N
Yates
John R
JR
Mitani
Shohei
S
Carrington
James C
JC
Mello
Craig C
CC
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000378:metabolism*; D016678:Genome / Q000235:genetics*; D005854:Germ Cells / Q000378:metabolism*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D018510:RNA, Helminth / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism; D017423:Sequence Analysis, RNA; D013696:Temperature
D029742:Caenorhabditis elegans Proteins; D018510:RNA, Helminth; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012324:RNA-Dependent RNA Polymerase