The dynamics of yeast telomeres and silencing proteins through the cell cycle.

Details

Serval ID
serval:BIB_0FFD48DCC432
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The dynamics of yeast telomeres and silencing proteins through the cell cycle.
Journal
Journal of Structural Biology
Author(s)
Laroche T., Martin S.G., Tsai-Pflugfelder M., Gasser S.M.
ISSN
1047-8477 (Print)
ISSN-L
1047-8477
Publication state
Published
Issued date
2000
Volume
129
Number
2-3
Pages
159-174
Language
english
Abstract
Genes integrated near the telomeres of budding yeast have a variegated pattern of gene repression that is mediated by the silent information regulatory proteins Sir2p, Sir3p, and Sir4p. Immunolocalization and fluorescence in situ hybridization (FISH) reveal 6-10 perinuclear foci in which silencing proteins and subtelomeric sequences colocalize, suggesting that these are sites of Sir-mediated repression. Telomeres lacking subtelomeric repeat elements and the silent mating locus, HML, also localize to the periphery of the nucleus. Conditions that disrupt telomere proximal repression disrupt the focal staining pattern of Sir proteins, but not necessarily the localization of telomeric DNA. To monitor the telomere-associated pools of heterochromatin-binding proteins (Sir and Rap1 proteins) during mitotic cell division, we have performed immunofluorescence and telomeric FISH on populations of yeast cells synchronously traversing the cell cycle. We observe a partial release of Rap1p from telomeres in late G2/M, although telomeres appear to stay clustered during G2-phase and throughout mitosis. A partial release of Sir3p and Sir4p during mitosis also occurs. This is not observed upon HU arrest, although other types of DNA damage cause a dramatic relocalization of Sir and Rap1 proteins. The observed cell cycle dynamics were confirmed by direct epifluorescence of a GFP-Rap1p fusion. Using live GFP fluorescence we show that the diffuse mitotic distribution of GFP-Rap1p is restored to the interphase pattern of foci in early G1-phase.
Keywords
Cell Cycle/genetics, Cell Nucleus/genetics, Cell Nucleus/physiology, Fungal Proteins/metabolism, Genes, Regulator, Genes, Reporter, Green Fluorescent Proteins, Luminescent Proteins/genetics, Mitosis, Recombinant Fusion Proteins/metabolism, Saccharomyces cerevisiae/cytology, Saccharomyces cerevisiae/genetics, Silent Information Regulator Proteins, Saccharomyces cerevisiae, Telomere/genetics, Telomere/physiology, Trans-Activators/metabolism
Pubmed
Web of science
Create date
18/03/2008 11:32
Last modification date
20/08/2019 12:36
Usage data