Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-11-20
pubmed:abstractText
Mouse hepatoma Hepa 1c1c7 cells and nonresponsive mutants have been extensively used as models for investigating the molecular mechanism of induction of CYP1A1 gene transcription by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. Incubation of cytosolic [3H]TCDD-aryl hydrocarbon (Ah) receptor from wild-type Hepa 1c1c7 cells for 16 h at 4 degrees C in 0.4 M KCl resulted in the formation of transformed liganded receptor which exhibited increased binding affinity on DNA-Sepharose columns. The elution properties of the peak with the highest DNA binding affinity were similar to the elution profiles of the nuclear receptor complex isolated from wild-type cells. TAOc1BPrcl (class I) nonresponsive mutant cells were characterized by relatively low levels of the cytosolic and nuclear Ah receptor complex. The BPrcl (class II) variant cell line contained levels of cytosolic receptor which were comparable to those observed in the wild-type cells; however, significantly reduced levels of nuclear receptor complex were observed in the class II variant cell line. Incubation of the nuclear or transformed liganded cytosolic Ah receptor from wild-type cells with a consensus 32P-labeled dioxin responsive element (DRE) in a gel shift assay gave a retarded band associated with the receptor-DRE complex. Incubation of the cytosolic receptor complex from the class I and II mutant cells for 16 h at 4 degrees C in 0.4 M KCl or for 2 h at 20 degrees C did not yield complexes with increasing binding affinities on DNA-Sepharose columns. Moreover, incubation of these complexes with 32P-labeled DRE did not give a retarded band in a gel shift assay. However, coincubation of the liganded class II mutant cytosol with cytosol from class I cells resulted in transformation of the liganded receptor and this was confirmed in both the DNA-Sepharose and gel retardation assays. These results suggest that the failure of class II mutant cells to respond to TCDD is due to a defect in the factors responsible for transformation of the cytosolic receptor complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
290
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
362-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
DNA binding properties of the Ah receptor in wild-type and variant mouse hepatoma cells.
pubmed:affiliation
Department of Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station 77843-4466.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't