RRC ID 75923
Author Charlesworth AG, Seroussi U, Lehrbach NJ, Renaud MS, Sundby AE, Molnar RI, Lao RX, Willis AR, Woock JR, Aber MJ, Diao AJ, Reinke AW, Ruvkun G, Claycomb JM.
Title Two isoforms of the essential C. elegans Argonaute CSR-1 differentially regulate sperm and oocyte fertility.
Journal Nucleic Acids Res
Abstract The Caenorhabditis elegans genome encodes nineteen functional Argonaute proteins that use 22G-RNAs, 26G-RNAs, miRNAs or piRNAs to regulate target transcripts. Only one Argonaute is essential under normal laboratory conditions: CSR-1. While CSR-1 has been studied widely, nearly all studies have overlooked the fact that the csr-1 locus encodes two isoforms. These isoforms differ by an additional 163 amino acids present in the N-terminus of CSR-1a. Using CRISPR-Cas9 genome editing to introduce GFP::3xFLAG into the long (CSR-1a) and short (CSR-1b) isoforms, we found that CSR-1a is expressed during spermatogenesis and in several somatic tissues, including the intestine. CSR-1b is expressed constitutively in the germline. small RNA sequencing of CSR-1 complexes shows that they interact with partly overlapping sets of 22G-RNAs. Phenotypic analyses reveal that the essential functions of csr-1 described in the literature coincide with CSR-1b, while CSR-1a plays tissue specific functions. During spermatogenesis, CSR-1a integrates into an sRNA regulatory network including ALG-3, ALG-4 and WAGO-10 that is necessary for fertility at 25°C. In the intestine, CSR-1a silences immunity and pathogen-responsive genes, and its loss results in improved survival from the pathogen Pseudomonas aeruginosa. Our findings functionally distinguish the CSR-1 isoforms and highlight the importance of studying each AGO isoform independently.
Volume 49(15)
Pages 8836-8865
Published 2021-9-7
DOI 10.1093/nar/gkab619
PII 6331683
PMID 34329465
PMC PMC8421154
MeSH Alleles Animals Caenorhabditis elegans / embryology Caenorhabditis elegans / genetics* Caenorhabditis elegans / growth & development Caenorhabditis elegans / metabolism Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Caenorhabditis elegans Proteins / physiology* Female Fertility Gene Expression Male Mutation Oocytes / metabolism Proteasome Endopeptidase Complex / metabolism Protein Isoforms / genetics Protein Isoforms / metabolism Protein Isoforms / physiology RNA, Small Untranslated / metabolism Spermatogenesis / genetics* Spermatozoa / metabolism
C.elegans tm892 tm1184 tm1155 tm1019