Linked Life Data

17705400

Source:http://linkedlifedata.com/resource/pubmed/id/17705400

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2007-9-4
pubmed:abstractText
Myc and Max belong to the b-HLH-LZ family of transcription factors. Heterodimerization between Myc and Max or homodimerization of Max allows these proteins to bind their cognate DNA sequence known as the E-box (CACGTG). Recent evidence has suggested that the c-Myc/Max heterodimeric b-HLH-LZ could interact to form a head-to-tail dimer of dimers and induce complex topologies such as loops in promoters containing more than one E-box sequence. In an attempt to shed light on this hypothesis, the interaction between the heterodimeric b-HLH-LZ of c-Myc/Max and a fragment of the hTERT promoter containing two E-box sequences was studied by atomic force microscopy. Specific binding events were observed at both E-box sites with equal probabilities. In accordance with previous results obtained by EMSA, we observed that the specific binding of the c-Myc/Max b-HLH-LZ bends the promoter. However no looping could be observed in a wide range of concentration encompassing the Ka (association constant) of the putative tetramer and the Ka for the specific binding of the heterodimer. In contrast, experiments performed with a mandatory c-Myc/Max b-HLH-LZ tetramer incubated with the hTERT promoter fragment allowed for the visualization of loops and cross-linked DNA strands originating from specific binding. Altogether, our results indicate that the c-Myc/Max b-HLH-LZ dimer binds specifically and equally to both E-box sites of the hTERT promoter and induces a significant bending of the promoter and that the suggested oligomerization of the c-Myc/Max heterodimeric b-HLH-LZ, if existing, is most likely too weak to induce the formation of a loop in a promoter.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10279-86
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Direct visualization of the binding of c-Myc/Max heterodimeric b-HLH-LZ to E-box sequences on the hTERT promoter.
pubmed:affiliation
Département de pharmacologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't