title: Trehalose and glycogen accumulation is related to the duration of the G1 phase of Saccharomyces cerevisiae.
abstract: Several factors may control trehalose and glycogen synthesis, like the glucose flux, the growth rate, the intracellular glucose-6-phosphate level and the glucose concentration in the medium. Here, the possible relation of these putative inducers to reserve carbohydrate accumulation was studied under well-defined growth conditions in nitrogen-limited continuous cultures. We showed that the amounts of accumulated trehalose and glycogen were regulated by the growth rate imposed on the culture, whereas other implicated inducers did not exhibit a correlation with reserve carbohydrate accumulation. Trehalose accumulation was induced at a dilution rate (D)</=0.10 h(-1), whereas glycogen accumulation gradually increased at decreasing growth rates. The growth rate dependency of trehalose accumulation was supported by studies in cells overexpressing the G(1)-cyclin CLN3. The trehalose level appeared to be dependent on the duration of the G(1) phase, as trehalose was only accumulated at a G(1) phase duration of more than 5 h in both wild-type and CLN3-overexpressing cells. On the other hand, the glycogen level was reduced by CLN3 overexpression in a cell cycle-independent manner. A possible regulatory mechanism that links trehalose and glycogen accumulation to the growth rate is discussed.
authors.affiliation: Department of Molecular Cell Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Johannes W G
authors.initials: JW
authors.lastname: Paalman
authors.forename: René
authors.initials: R
authors.lastname: Verwaal
authors.forename: Sjoukje H
authors.initials: SH
authors.lastname: Slofstra
authors.forename: Arie J
authors.initials: AJ
authors.lastname: Verkleij
authors.forename: Johannes
authors.initials: J
authors.lastname: Boonstra
authors.forename: C Theo
authors.initials: CT
authors.lastname: Verrips
mesh_terms: D002244:Carbon / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology; D003470:Culture Media; D056746:Cyclin G; D016213:Cyclins / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase / Q000502:physiology; D015966:Gene Expression Regulation, Fungal; D006003:Glycogen / Q000096:biosynthesis*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013997:Time Factors; D014199:Trehalose / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D056746:Cyclin G; D016213:Cyclins; D002244:Carbon; D006003:Glycogen; D014199:Trehalose