biostudies-literatureSmith PRU.S. Department of Health & Human Services | NIH | National Institute of Neurological Disorders and StrokeNINDS NIH HHS6789https://www.ebi.ac.uk/biostudies/studies/S-EPMC8611098biostudies-literatureUnknown12(1)Processing bodies (p-bodies) are a prototypical phase-separated RNA-containing granule. Their abundance is highly dynamic and has been linked to translation. Yet, the molecular mechanisms responsible for coordinate control of the two processes are unclear. Here, we uncover key roles for eEF2 kinase (eEF2K) in the control of ribosome availability and p-body abundance. eEF2K acts on a sole known substrate, eEF2, to inhibit translation. We find that the eEF2K agonist nelfinavir abolishes p-bodies in sensory neurons and impairs translation. To probe the latter, we used cryo-electron microscopy. Nelfinavir stabilizes vacant 80S ribosomes. They contain SERBP1 in place of mRNA and eEF2 in the acceptor site. Phosphorylated eEF2 associates with inactive ribosomes that resist splitting in vitro. ColNature communicationsFunctionally distinct roles for eEF2K in the control of ribosome availability and p-body abundance.PMC8611098R01NS114018R01 NS100788R01NS100788R01 NS114018Lou TFLoerch SCampbell ZTStanowick ADSmith PRKunder NfalseFunctionally distinct roles for eEF2K in the control of ribosome availability and p-body abundance.Processing bodies (p-bodies) are a prototypical phase-separated RNA-containing granule. Their abundance is highly dynamic and has been linked to translation. Yet, the molecular mechanisms responsible for coordinate control of the two processes are unclear. Here, we uncover key roles for eEF2 kinase (eEF2K) in the control of ribosome availability and p-body abundance. eEF2K acts on a sole known substrate, eEF2, to inhibit translation. We find that the eEF2K agonist nelfinavir abolishes p-bodies in sensory neurons and impairs translation. To probe the latter, we used cryo-electron microscopy. Nelfinavir stabilizes vacant 80S ribosomes. They contain SERBP1 in place of mRNA and eEF2 in the acceptor site. Phosphorylated eEF2 associates with inactive ribosomes that resist splitting in vitro. Col2021-01-01T00:00:00Z2021 Nov2026-05-09T17:19:58.89Z2022-02-11T13:29:51.801ZS-EPMC86110983481542410.1038/s41467-021-27160-4