Fig. 1

TASOR is phosphorylated on threonine 819 in early mitosis. A SAMHD1 and TASOR proteins are represented with their major characteristics. SAMHD1 is depicted with its nuclear localization signal, SAM and HD domains. TASOR is depicted according to Douse et al. [34] with PARP-like, SPOC, and PIN domains. DomI and DomII correspond to ordered regions with no structural homology. The sequence surrounding SAMHD1 T592 phosphorylation site is indicated together with the upstream Cyclin binding motif. TASOR harbors a similar consensus surrounding T819 with also an upstream Cyclin binding motif. B Hela cells were transfected by empty vectors or vectors encoding for wt TASOR or TASOR T819A, both tagged with the Flag peptide. 48 h later, cells were treated by nocodazole for 18 h. Immunoprecipitation was carried out using anti-Flag antibodies, and indicated proteins were detected using anti-Flag or anti-phospho antibodies raised against a phospho-peptide surrounding TASOR T819. C HeLa cells were arrested in early mitosis by nocodazole for 18 h, then washed and released in complete media for the indicated time points. As: Asynchronous cells. D Same as in C but with Jurkat T cells. E CD4 + quiescent T cells from a healthy donor were activated with CD3 and CD28 antibodies. Following activation, cells were treated with drugs as indicated and 18 h later, harvested for western blot analysis