title: Golgi enlargement in Arf-depleted yeast cells is due to altered dynamics of cisternal maturation.
abstract: Regulation of the size and abundance of membrane compartments is a fundamental cellular activity. In Saccharomyces cerevisiae, disruption of the ADP-ribosylation factor 1 (ARF1) gene yields larger and fewer Golgi cisternae by partially depleting the Arf GTPase. We observed a similar phenotype with a thermosensitive mutation in Nmt1, which myristoylates and activates Arf. Therefore, partial depletion of Arf is a convenient tool for dissecting mechanisms that regulate Golgi structure. We found that in arf1Δ cells, late Golgi structure is particularly abnormal, with the number of late Golgi cisternae being severely reduced. This effect can be explained by selective changes in cisternal maturation kinetics. The arf1Δ mutation causes early Golgi cisternae to mature more slowly and less frequently, but does not alter the maturation of late Golgi cisternae. These changes quantitatively explain why late Golgi cisternae are fewer in number and correspondingly larger. With a stacked Golgi, similar changes in maturation kinetics could be used by the cell to modulate the number of cisternae per stack. Thus, the rates of processes that transform a maturing compartment can determine compartmental size and copy number.
authors.affiliation: Advanced Centre for Treatment Research & Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, 410210 MH, India.
authors.forename: Madhura
authors.initials: M
authors.lastname: Bhave
authors.forename: Effrosyni
authors.initials: E
authors.lastname: Papanikou
authors.forename: Prasanna
authors.initials: P
authors.lastname: Iyer
authors.forename: Koushal
authors.initials: K
authors.lastname: Pandya
authors.forename: Bhawik Kumar
authors.initials: BK
authors.lastname: Jain
authors.forename: Abira
authors.initials: A
authors.lastname: Ganguly
authors.forename: Chandrakala
authors.initials: C
authors.lastname: Sharma
authors.forename: Ketakee
authors.initials: K
authors.lastname: Pawar
authors.forename: Jotham
authors.initials: J
authors.lastname: Austin
authors.forename: Kasey J
authors.initials: KJ
authors.lastname: Day
authors.forename: Olivia W
authors.initials: OW
authors.lastname: Rossanese
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Glick
authors.forename: Dibyendu
authors.initials: D
authors.lastname: Bhattacharyya
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000172:deficiency / Q000235:genetics*; D001692:Biological Transport; D015966:Gene Expression Regulation, Fungal; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D009154:Mutation; D009227:Myristic Acids / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D009227:Myristic Acids; D029701:Saccharomyces cerevisiae Proteins; D020823:ADP-Ribosylation Factor 1
keywords: Arf; Cisternal maturation; Golgi; Organelle number; Organelle size