title: Checkpoint control of mitotic exit--do budding yeast mind the GAP?
abstract: Cell cycle checkpoints can delay mitotic exit in budding yeast. The master controller is the small GTPase Tem1, with inputs from a proposed guanine nucleotide exchange factor (GEF), Lte1, and a GTPase-activating protein (GAP), Bub2/Bfa1. In this issue, Fraschini et al. (p. 335) show that GAP activity of Bub2/Bfa1 appears to be dispensable for inactivation of Tem1 in cells. Their results call into question the GTP/GDP switch model for Tem1 activity, as have other results in the past. The paper also focuses attention on the two spindle pole bodies as potential sites for regulation of Tem1.
authors.affiliation: Department of Cell Biology, Washington University, St. Louis, MO 63110, USA. jcooper@wustl.edu
authors.forename: John A
authors.initials: JA
authors.lastname: Cooper
authors.forename: Scott A
authors.initials: SA
authors.lastname: Nelson
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000502:physiology*; D008938:Mitosis / Q000502:physiology*; D008957:Models, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology; D008941:Spindle Apparatus / Q000235:genetics / Q000502:physiology
chemical_list: D018797:Cell Cycle Proteins; D020690:GTPase-Activating Proteins; D029701:Saccharomyces cerevisiae Proteins