FG repeats drive co-clustering of nuclear pores and P granules in the C. elegans germline

Abstract

Condensates that accumulate small RNA biogenesis factors (nuage) are common in germ cells and often associate with nuclei. In the Caenorhabditis elegans germline, P granules overlay large clusters of nuclear pores and this organization has been proposed to facilitate surveillance of nascent transcripts by Argonaute proteins enriched in P granules. We report that co-clustering of nuclear pores and P granules depends on FG repeat-containing nucleoporins and FG repeats in the Vasa class helicase GLH-1. Worms with mutations that prevent this co-clustering are fertile under standard growth conditions and exhibit misregulation of only a minority of genes, including replication-dependent histones. Our observations suggest that association with nuclear pores, although non-essential for genome surveillance, may serve to tune mRNA flow through P granules and other nuage condensates.

Keywords: C. elegans; Germ granule; Histone; Nuclear pore; P granule.