Saura A. auteur aut IRD Iribarren P.A. auteur aut IRD Rojas-Barros D. auteur aut IRD Bart Jean-Mathieu auteur aut IRD López-Farfán D. auteur aut IRD Andrés-León E. auteur aut IRD Vidal-Cobo I. auteur aut IRD Boehm C. auteur aut IRD Alvarez V.E. auteur aut IRD Field M.C. auteur aut IRD Navarro M. auteur aut IRD text journalArticle eng text/pdf reformatted digital access SUMOylation is a post-translational modification that positively regulates monoallelic expression of the trypanosome variant surface glycoprotein (VSG). The presence of a highly SUMOylated focus associated with the nuclear body, where the VSG gene is transcribed, further suggests an important role of SUMOylation in regulating VSG expression. Here, we show that SNF2PH, a SUMOylated plant homeodomain (PH)-transcription factor, is upregulated in the bloodstream form of the parasite and enriched at the active VSG telomere. SUMOylation promotes the recruitment of SNF2PH to the VSG promoter, where it is required to maintain RNA polymerase I and thus to regulate VSG transcript levels. Further, ectopic overexpression of SNF2PH in insect forms, but not of a mutant lacking the PH domain, induces the expression of bloodstream stage-specific surface proteins. These data suggest that SNF2PH SUMOylation positively regulates VSG monoallelic transcription, while the PH domain is required for the expression of bloodstream-specific surface proteins. Thus, SNF2PH functions as a positive activator, linking expression of infective form surface proteins and VSG regulation, thereby acting as a major regulator of pathogenicity. specialized AFRIQUE 052 020 20 12 e48029 [18 ] 2019 1469-221X https://www.documentation.ird.fr/hor/fdi:010080152 10.15252/embr.201948029 1469-221X [F B010080152] https://www.documentation.ird.fr/hor/fdi:010080152 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers20-11/010080152.pdf IRD - Base Horizon / Pleins textes 2020-11-30 2025-02-24 fdi:010080152 fre