title: The PIAS homologue Siz2 regulates perinuclear telomere position and telomerase activity in budding yeast.
abstract: Budding yeast telomeres are reversibly bound at the nuclear envelope through two partially redundant pathways that involve the Sir2/3/4 silencing complex and the Yku70/80 heterodimer. To better understand how this is regulated, we studied the role of SUMOylation in telomere anchoring. We find that the PIAS-like SUMO E3 ligase Siz2 sumoylates both Yku70/80 and Sir4 in vivo and promotes telomere anchoring to the nuclear envelope. Remarkably, loss of Siz2 also provokes telomere extension in a telomerase-dependent manner that is epistatic with loss of the helicase Pif1. Consistent with our previously documented role for telomerase in anchorage, normal telomere anchoring in siz2 Δ is restored by PIF1 deletion. By live-cell imaging of a critically short telomere, we show that telomeres shift away from the nuclear envelope when elongating. We propose that SUMO-dependent association with the nuclear periphery restrains bound telomerase, whereas active elongation correlates with telomere release.
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
authors.forename: Helder C
authors.initials: HC
authors.lastname: Ferreira
authors.forename: Brian
authors.initials: B
authors.lastname: Luke
authors.forename: Heiko
authors.initials: H
authors.lastname: Schober
authors.forename: Véronique
authors.initials: V
authors.lastname: Kalck
authors.forename: Joachim
authors.initials: J
authors.lastname: Lingner
authors.forename: Susan M
authors.initials: SM
authors.lastname: Gasser
mesh_terms: D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009154:Mutation; D009685:Nuclear Envelope / Q000201:enzymology*; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D058207:Sumoylation; D019098:Telomerase / Q000378:metabolism*; D016615:Telomere / Q000201:enzymology*; D013997:Time Factors
chemical_list: D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C061573:SIR4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; C436836:Siz2 protein, S cerevisiae; C520769:YKU70 protein, S cerevisiae; C520770:YKU80 protein, S cerevisiae; D019098:Telomerase; C085463:PIF1 protein, S cerevisiae; D004265:DNA Helicases