The Dynamics of P Granule Liquid Droplets Are Regulated by the Caenorhabditis elegans Germline RNA Helicase GLH-1 via Its ATP Hydrolysis Cycle.

P granules are phase-separated liquid droplets that play important roles in the maintenance of germ cell fate in Caenorhabditis elegans. Both the localization and formation of P granules are highly dynamic, but mechanisms that regulate such processes remain poorly understood. Here, we show evidence that the VASA-like germline RNA helicase couples distinct steps of its ATPase hydrolysis cycle to control the formation and disassembly of P granules. In addition, we found that the phenylalanine-glycine-glycine repeats in promote its localization at the perinucleus. Proteomic analyses of the complex with a mutation that interferes with P granule disassembly revealed transient interactions of with several Argonautes and RNA-binding proteins. Finally, we found that defects in recruiting the P granule component to perinuclear foci in the adult germline correlate with the fertility defects observed in various mutants. Together, our results highlight the versatile roles of an RNA helicase in controlling the formation of liquid droplets in space and time.