The structure of human telomeres is not yet completely characterized. Several proteins involved in the formation of the human telomeric complex have been identified, such as hTRF1 and hTRF2 which bind to GGGTAA duplex telomeric repeats. Notwithstanding most human telomeric DNA is organized into tightly spaced nucleosomes, the role of nucleosomes in telomeric chromatin is largely unknown. We previously found that telomeric nucleosomes are less stable than bulk nucleosomes and occupy multiple isoenergetic positions spaced every telomere repeat, due to the peculiar features of telomeric repeated sequences. We will present data on some important sequence-dependent features of telomeric nucleosomes, such as intrinsic nucleosome mobility and the assembly in the 30 nm fiber, by means of an in vitro model system, AFM visualization and theoretical calculations. Data on the interaction of telomeric nucleosomes with the proteins hTRF1 and hTRF2 will be also presented.
The role of DNA sequence in telomeric chromatin features / Cacchione, Stefano; Savino, Maria. - STAMPA. - (2005). (Intervento presentato al convegno EMBO Workshop - Chromosome structural elements: from DNA sequence to function. tenutosi a Villa Mondragone, Monte Porzio Catone, Roma nel 29 set-3 ott 2005).
The role of DNA sequence in telomeric chromatin features
CACCHIONE, Stefano;SAVINO, Maria
2005
Abstract
The structure of human telomeres is not yet completely characterized. Several proteins involved in the formation of the human telomeric complex have been identified, such as hTRF1 and hTRF2 which bind to GGGTAA duplex telomeric repeats. Notwithstanding most human telomeric DNA is organized into tightly spaced nucleosomes, the role of nucleosomes in telomeric chromatin is largely unknown. We previously found that telomeric nucleosomes are less stable than bulk nucleosomes and occupy multiple isoenergetic positions spaced every telomere repeat, due to the peculiar features of telomeric repeated sequences. We will present data on some important sequence-dependent features of telomeric nucleosomes, such as intrinsic nucleosome mobility and the assembly in the 30 nm fiber, by means of an in vitro model system, AFM visualization and theoretical calculations. Data on the interaction of telomeric nucleosomes with the proteins hTRF1 and hTRF2 will be also presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
