title: A quantitative telomeric chromatin isolation protocol identifies different telomeric states.
abstract: Telomere composition changes during tumourigenesis, aging and in telomere syndromes in a poorly defined manner. Here we develop a quantitative telomeric chromatin isolation protocol (QTIP) for human cells, in which chromatin is cross-linked, immunopurified and analysed by mass spectrometry. QTIP involves stable isotope labelling by amino acids in cell culture (SILAC) to compare and identify quantitative differences in telomere protein composition of cells from various states. With QTIP, we specifically enrich telomeric DNA and all shelterin components. We validate the method characterizing changes at dysfunctional telomeres, and identify and validate known, as well as novel telomere-associated polypeptides including all THO subunits, SMCHD1 and LRIF1. We apply QTIP to long and short telomeres and detect increased density of SMCHD1 and LRIF1 and increased association of the shelterins TRF1, TIN2, TPP1 and POT1 with long telomeres. Our results validate QTIP to study telomeric states during normal development and in disease.
authors.affiliation: 1] EPFL-Ecole Polytechnique Fédérale de Lausanne, School of Life Sciences, CH-1015 Lausanne, Switzerland [2] ISREC-Swiss Institute fro Experimental Cancer Research at EPFL, CH-1015 Lausanne, Switzerland [3].
authors.forename: Larissa
authors.initials: L
authors.lastname: Grolimund
authors.forename: Eric
authors.initials: E
authors.lastname: Aeby
authors.forename: Romain
authors.initials: R
authors.lastname: Hamelin
authors.forename: Florence
authors.initials: F
authors.lastname: Armand
authors.forename: Diego
authors.initials: D
authors.lastname: Chiappe
authors.forename: Marc
authors.initials: M
authors.lastname: Moniatte
authors.forename: Joachim
authors.initials: J
authors.lastname: Lingner
mesh_terms: D001671:Biochemistry / Q000379:methods*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006570:Heterochromatin / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000089804:Shelterin Complex; D016615:Telomere / Q000737:chemistry* / Q000378:metabolism; D059506:Telomere Shortening; D034501:Telomere-Binding Proteins
chemical_list: C495876:ACD protein, human; D006570:Heterochromatin; D011506:Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D004247:DNA