Linked Life Data

17085443

Source:http://linkedlifedata.com/resource/pubmed/id/17085443

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-1-15
pubmed:abstractText
The retinal pigment epithelium (RPE) is crucial for the function and survival of retinal photoreceptors. VMD2 encodes bestrophin, an oligomeric chloride channel that is preferentially expressed in the RPE and, when mutated, causes Best macular dystrophy. Previously, we defined the VMD2 upstream region from -253 to +38 bp as being sufficient to direct RPE-specific expression in the eye, and we suggested microphthalmia-associated transcription factor (MITF) as a possible positive regulator. Here we show that in transgenic mice the -154 to +38 bp region is sufficient for RPE expression, and mutation of two E-boxes, 1 and 2, within this region leads to loss of promoter activity. A yeast one-hybrid screen using bait containing E-box 1 identified clones encoding MITF, TFE3, and TFEB, and chromatin immunoprecipitation with antibodies against these proteins enriched the VMD2 proximal promoter. Analysis using in vivo electroporation with constructs containing mutation of each E-box indicated that expression in native RPE requires both E-boxes, yet in vitro DNA binding studies suggested that MITF binds well to E-box 1 but only minimally to E-box 2. MITF knockdown by small interfering RNA (siRNA) in cell culture revealed a strong correlation between MITF and VMD2 mRNA levels. Sequential transfection of a luciferase construct with expression vectors following MITF siRNA revealed that TFE3 and TFEB can also transactivate the VMD2 promoter. Taken together, we suggest that VMD2 is regulated by the MITF-TFE family through two E-boxes, with E-box 1 required for a direct interaction of MITF-TFE factors and E-box 2 for binding of the as yet unidentified factor(s).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1838-50
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
VMD2 promoter requires two proximal E-box sites for its activity in vivo and is regulated by the MITF-TFE family.
pubmed:affiliation
The Guerrieri Center for Genetic Engineering and Molecular Ophthalmology, The Wilmer Eye Institute, the Departments of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-9289, USA. nesumi@jhmi.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural