RESEARCH ARTICLE AIRE is a critical spindle-associated protein in embryonic stem cells Bin Gu1, Jean-Philippe Lambert2, Katie Cockburn1, Anne-Claude Gingras2,3, Janet Rossant1,3* 1Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada; 2Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, Toronto, Canada; 3Department of Molecular Genetics, University of Toronto, Toronto, Canada Abstract Embryonic stem (ES) cells go though embryo-like cell cycles regulated by specialized molecular mechanisms. However, it is not known whether there are ES cell-specific mechanisms regulating mitotic fidelity. Here we showed that Autoimmune Regulator (Aire), a transcription coordinator involved in immune tolerance processes, is a critical spindle-associated protein in mouse ES(mES) cells. BioID analysis showed that AIRE associates with spindle-associated proteins in mES cells. Loss of function analysis revealed that Aire was important for centrosome number regulation and spindle pole integrity specifically in mES cells. We also identified the c-terminal LESLL motif as a critical motif for AIRE’s mitotic function. Combined maternal and zygotic knockout further revealed Aire’s critical functions for spindle assembly in preimplantation embryos. These results uncovered a previously unappreciated function for Aire and provide new insights into the biology of stem cell proliferation and potential new angles to understand fertility defects in humans carrying Aire mutations. DOI: 10.7554/eLife.28131.001 *For correspondence: janet.
[email protected] Introduction Competing interests: The Self-renewal capability, defined as the ability of cells to proliferate while sustaining differentiation authors declare that no potential, is one of the defining features of stem cells (Martello and Smith, 2014).