TY - JOUR
T1 - Protein-DNA interactions in soluble telosomes from Saccharomyces cerevisiae
AU - Wright, Jocelyn H.
AU - Zakian, Virginia A.
N1 - Funding Information:
We thank M. Roberge and S. Gasser for the L355 plasmid for expression of Raplp in E.coli, A. Carmen and M. Grunstein for advice on and reagents for yeast histones, E. Louis and J. Haber for the clone used to make the X probes, and B. Bourns and J.-J. Lin for their comments on the manuscript. This work was supported by GM43265 from the National Institutes of Health. Jocelyn H. Wright was supported in part by the Molecular Training Program in Cancer Research training grant through the Department of Pathology at the University of Washington.
PY - 1995/5/11
Y1 - 1995/5/11
N2 - Telomerlc DNA in Saccharomyces Is organized into a non-nucleosomal chromatin structure called the telo-some that can be released from chromosome ends in soluble form by nuclease digestion (Wright, J. H., Gottschling, D. E. and Zakian, V. A. (1992) Genes Dev. 6, 197-210). The protein-DNA Interactions of soluble telosomes were investigated by monitoring isolated telomeric DNA fragments for the retention of bound protein using both gel mobility shift and nitrocellulose filter-binding assays. Telosomal proteins remained associated with telomeric DNA at concentrations of ethidlum bromide that dissociated nucleosomes. The protein-DNA Interactions In the yeast telosome were also disrupted by much lower salt concentrations than those known to disrupt either the interactions of ciliate terminus-binding proteins with telomeric DNA or the Interactions of hlstones with DNA in nucleosomes. Taken together, these data corroborate previously published nuclease mapping data indicating that telosomes are distinct in structure from conventional nucleosomes. These data also Indicate that yeast do not possess telomere binding proteins similar to those detected in ciliates that remain tightly bound to telomeric DNA even in high salt. In addition, the characteristic gel mobility shift of soluble telosomes could be mimicked by complexes formed In vitro with yeast telomeric DNA and recombinant Rap1p suggesting that Rap1 p, a known component of soluble yeast telosomes (Wright, J. H., Gottschling, D. E. and Zakian, V. A. (1992) Genes Dev. 6, 197-210; Conrad, M. N., Wright, J. H., Wolf, A. J. and Zakian, V. A. (1990) Cell63, 739-750), Is likely to be the major structural protein bound directly to yeast telomeric DNA.
AB - Telomerlc DNA in Saccharomyces Is organized into a non-nucleosomal chromatin structure called the telo-some that can be released from chromosome ends in soluble form by nuclease digestion (Wright, J. H., Gottschling, D. E. and Zakian, V. A. (1992) Genes Dev. 6, 197-210). The protein-DNA Interactions of soluble telosomes were investigated by monitoring isolated telomeric DNA fragments for the retention of bound protein using both gel mobility shift and nitrocellulose filter-binding assays. Telosomal proteins remained associated with telomeric DNA at concentrations of ethidlum bromide that dissociated nucleosomes. The protein-DNA Interactions In the yeast telosome were also disrupted by much lower salt concentrations than those known to disrupt either the interactions of ciliate terminus-binding proteins with telomeric DNA or the Interactions of hlstones with DNA in nucleosomes. Taken together, these data corroborate previously published nuclease mapping data indicating that telosomes are distinct in structure from conventional nucleosomes. These data also Indicate that yeast do not possess telomere binding proteins similar to those detected in ciliates that remain tightly bound to telomeric DNA even in high salt. In addition, the characteristic gel mobility shift of soluble telosomes could be mimicked by complexes formed In vitro with yeast telomeric DNA and recombinant Rap1p suggesting that Rap1 p, a known component of soluble yeast telosomes (Wright, J. H., Gottschling, D. E. and Zakian, V. A. (1992) Genes Dev. 6, 197-210; Conrad, M. N., Wright, J. H., Wolf, A. J. and Zakian, V. A. (1990) Cell63, 739-750), Is likely to be the major structural protein bound directly to yeast telomeric DNA.
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U2 - 10.1093/nar/23.9.1454
DO - 10.1093/nar/23.9.1454
M3 - Article
C2 - 7784196
AN - SCOPUS:0029020783
SN - 0305-1048
VL - 23
SP - 1454
EP - 1460
JO - Nucleic acids research
JF - Nucleic acids research
IS - 9
ER -