The C. elegans SNAPc component SNPC-4 coats piRNA domains and is globally required for piRNA abundance.
The Piwi/Piwi-interacting RNA (piRNA) pathway protects the germline from the activity of foreign sequences such as transposons. Remarkably, tens of thousands of piRNAs arise from a minimal number of discrete genomic regions. The extent to which clustering of these small RNA genes contributes to their coordinated expression remains unclear. We show that C. elegans SNPC-4, the Myb-like DNA-binding subunit of the small nuclear RNA activating protein complex, binds piRNA clusters in a germline-specific manner and is required for global piRNA expression. SNPC-4 localization is mutually dependent with localization of piRNA biogenesis factor PRDE-1. SNPC-4 exhibits an atypical widely distributed binding pattern that "coats" piRNA domains. Discrete peaks within the domains occur frequently at RNA-polymerase-III-occupied transfer RNA (tRNA) genes, which have been implicated in chromatin organization. We suggest that SNPC-4 binding establishes a positive expression environment across piRNA domains, providing an explanation for the conserved clustering of individually transcribed piRNA genes.
Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
Dionna M
DM
Kasper
Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
Guilin
G
Wang
Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
Kathryn E
KE
Gardner
Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
Timothy G
TG
Johnstone
Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA. Electronic address: valerie.reinke@yale.edu.
Valerie
V
Reinke
D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D044127:Epigenesis, Genetic; D012320:RNA Polymerase III / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D029742:Caenorhabditis elegans Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; D014157:Transcription Factors; C516320:Zim-3 protein, C elegans; C415502:unc-130 protein, C elegans; D012320:RNA Polymerase III