Elucidation of the telomeric proteome by QTIP

A fundamental aspect of telomeres is the complexity of their composition and their dynamic nature. To tackle the molecular changes that occur at telomeres during normal development, in cancer and in telomere syndromes, we established a Quantitative Telomeric chromatin Isolation Protocol (QTIP), which allows the biochemical isolation and analysis of the telomeric nucleoprotein complexes. Combined with SILAC or TMT labeling and mass spectrometry, the QTIP technique enables comparison of different physiological and pathological telomeric states. Our analysis uncovered novel telomeric factors that associate with intact or damaged telomeres. Recently, we also adapted the QTIP method to determine the composition of the telomeric replisome and the mechanisms of telomere replication.