title: Regulation of Golgi Cisternal Progression by Ypt/Rab GTPases.
abstract: Current models entail that transport through the Golgi-the main sorting compartment of the cell-occurs via cisternal progression/maturation and that Ypt/Rab GTPases regulate this process. However, there is very limited evidence that cisternal progression is regulated, and no evidence for involvement of Ypt/Rab GTPases in such a regulation. Moreover, controversy about the placement of two of the founding members of the Ypt/Rab family, Ypt1 and Ypt31, to specific Golgi cisternae interferes with addressing this question in yeast, where cisternal progression has been extensively studied. Here, we establish the localization of Ypt1 and Ypt31 to opposite faces of the Golgi: early and late, respectively. Moreover, we show that they partially overlap on a transitional compartment. Finally, we determine that changes in Ypt1 and Ypt31 activity affect Golgi cisternal progression, early-to-transitional and transitional-to-late, respectively. These results show that Ypt/Rab GTPases regulate two separate steps of Golgi cisternal progression.
authors.affiliation: Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
authors.forename: Jane J
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Molecular Biology Research Building, 900 South Ashland Avenue, Chicago, IL 60607, USA.
authors.forename: Zhanna
authors.initials: Z
authors.lastname: Lipatova
authors.affiliation: Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Molecular Biology Research Building, 900 South Ashland Avenue, Chicago, IL 60607, USA.
authors.forename: Uddalak
authors.initials: U
authors.lastname: Majumdar
authors.affiliation: Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Molecular Biology Research Building, 900 South Ashland Avenue, Chicago, IL 60607, USA. Electronic address: nava@uic.edu.
authors.forename: Nava
authors.initials: N
authors.lastname: Segev
mesh_terms: D001692:Biological Transport; D006056:Golgi Apparatus / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; C087905:YPT31 protein, S cerevisiae; C060755:YPT1 protein, S cerevisiae; D020691:rab GTP-Binding Proteins