SUMOylation of SAMHD1 at Lysine 595 is required for HIV-1 restriction in non-cycling cells

Charlotte Martinat, Arthur Cormier, Joëlle Tobaly-Tapiero, Noé Palmic, Nicoletta Casartelli, Bijan Mahboubi, Si’Ana A.A. Coggins, Julian Buchrieser, Mirjana Persaud, Felipe Diaz-Griffero, Lucile Espert, Guillaume Bossis, Pascale Lesage, Olivier Schwartz, Baek Kim, Florence Margottin-Goguet, Ali Saïb, Alessia Zamborlini

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


SAMHD1 is a cellular triphosphohydrolase (dNTPase) proposed to inhibit HIV-1 reverse transcription in non-cycling immune cells by limiting the supply of the dNTP substrates. Yet, phosphorylation of T592 downregulates SAMHD1 antiviral activity, but not its dNTPase function, implying that additional mechanisms contribute to viral restriction. Here, we show that SAMHD1 is SUMOylated on residue K595, a modification that relies on the presence of a proximal SUMO-interacting motif (SIM). Loss of K595 SUMOylation suppresses the restriction activity of SAMHD1, even in the context of the constitutively active phospho-ablative T592A mutant but has no impact on dNTP depletion. Conversely, the artificial fusion of SUMO2 to a non-SUMOylatable inactive SAMHD1 variant restores its antiviral function, a phenotype that is reversed by the phosphomimetic T592E mutation. Collectively, our observations clearly establish that lack of T592 phosphorylation cannot fully account for the restriction activity of SAMHD1. We find that SUMOylation of K595 is required to stimulate a dNTPase-independent antiviral activity in non-cycling immune cells, an effect that is antagonized by cyclin/CDK-dependent phosphorylation of T592 in cycling cells.

Original languageEnglish (US)
Article number4582
JournalNature communications
Issue number1
StatePublished - Dec 1 2021

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)


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