Septation failure is associated with a block in secretion of the septum degrading enzyme Cts1. (A) Cts1 transcript induction is not altered upon failed septation. CTS1 mRNA from cells in B were measured by qPCR at the time indicated after release. The fold change in CTS1 mRNA (normalized to ACT1) relative to −Auxin at time 0 is shown. A representative time course from two independent experiments is shown. (B) Cts1 secretion is blocked when septation fails. inn1-AID cells expressing HA-tagged Cts1 were synchronized in mitosis and treated with DMSO (−Auxin) or 0.5 mM auxin (+Auxin). Protein was collected at the indicated times following mitotic release at 25°C. A Western blot of secreted Cts1 (top panel) and internal pool of Cts1 (middle panel) is shown. The asterisk indicates a nonspecific band (see Fig. S1 C). Hxk2 and the cyclin Clb2 are shown as a loading and cell cycle release control, respectively (lower panels). A representative blot is shown (see also Fig. S1). (C) Western blot quantification. Fold change in the signal of secreted Cts1 (upper panel) and internal Cts1 (lower panel) relative to the maximum signal in the −Auxin control is shown. Error bars represent the SD from three independent time courses.