Two S. pombe septation phases differ in ingression rate, septum structure, and response to F-actin loss

• DOI: 10.1083/jcb.201808163
• Publication Date: 2019-10-09T19:35:14Z
• Authors: Mariona Ramos; Juan Carlos G. Co...; Mamiko Sato; Sergio A. Rincón; M. Belén Moreno; José Ángel Clemen...; Masako Osumi; Pilar Pérez; Juan Carlos Ribas
• Keywords: Ingression; Exocyst; Septin

In fission yeast, cytokinesis requires a contractile actomyosin ring (CR) coupled to membrane and septum ingression. Septation proceeds in two phases. anaphase B, the ingresses slowly. During telophase, ingression rate increases, CR becomes dispensable. Here, we explore relationship between septation by analyzing ultrastructure, ingression, proteins cells lacking F-actin. We show that phases of correlate with maturation response F-actin removal. first phase, is immature and, following removal, rapidly loses Bgs1 glucan synthase from edge fails ingress. second ingressing mature can maintain without F-actin, but Cdc42 exocyst dependent. Our results provide new insights into fungal reveal dual function as an essential landmark for concentration structure maintains shape synthesis.