Linked Life Data

2492326

Source:http://linkedlifedata.com/resource/pubmed/id/2492326

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-3-1
pubmed:abstractText
The class II (Ia) MHC Ag are integral membrane proteins whose expression is limited to specific cell types. A pair of consensus sequences, X and Y, is found upstream from all class II genes and deletion of each of these sequences eliminates expression of transfected genes. Cells that express Ia demonstrate a coordinate response to lymphokines and other stimuli. These conserved sequences might, therefore, play a role in tissue specificity or lymphokine inducibility of Ia gene expression. The X box sequence of the murine class II A alpha gene diverges much more substantially from the X consensus than does the Y box motif of this gene. We demonstrate that this X box motif is nonetheless recognized by sequence-specific DNA-binding proteins, as is the more closely conserved Y box. Gel retardation assays and DNase I footprints were compared for a panel of Ia+ and Ia- cells as well as for cells stimulated with the Ia-inducing lymphokines IL-4 and IFN-gamma. The level, retardation pattern and region of DNA contact were comparable in all instances. Thus the availability of active DNA-binding X and Y box factors cannot alone account for the regulation of A alpha expression. To test whether the same set of proteins binds all class II MHC conserved motifs, oligonucleotide probe binding and cross-competition experiments with X box sequences from A alpha, E alpha, and E beta genes were performed. These studies demonstrated A alpha, E alpha, and E beta DNA-protein complexes with unique mobilities and specificities. In addition, all three X box oligonucleotide probes generated one faint complex with an affinity profile of E beta greater than E alpha much greater than A alpha. These three complexes comigrated and thus may represent a communal binding protein. The data are most consistent with the conclusion that multiple proteins bind class II MHC X boxes. For A alpha, the predominant complexes represent different specificities from the predominant E alpha and E beta X box binding proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
142
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1005-14
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Differences in DNA sequence specificity among MHC class II X box binding proteins.
pubmed:affiliation
Department of Cancer Biology, Harvard School of Public Health, Boston, MA 02155.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't