A mechanism of differential expression of GLUT2 in hepatocyte and pancreatic beta-cell line
Experimental & Molecular Medicine
;
: 15-20, 1998.
Article
in English
| WPRIM
| ID: wpr-192962
ABSTRACT
DNase I footprinting assay using liver nuclear extracts revealed six protected regions between nucleotide -600 and +110 and hence named Box I-VI. Upstream promoter element (UPE), a DNA element playing crucial role in transcriptional control of the tissue specific expression of pancreatic beta-cell, has been detected within the proximal region of rat GLUT2 promoter. This region is included in Box VI. The protein-DNA interaction in this region (Box VI) was confirmed by mobility shift assay using liver nuclear extracts. Deletion of the region between -585 bp and -146 bp resulted in dramatic changes in promoter activity when they were expressed in liver and beta-cell derived cell line. When -585/-146 construct was expressed in liver, the activity was decreased to 46%, whereas the activity in beta-cell line, HIT-T15 cell, was increased by 84% when compared to -146/+190 construct. These opposing phenomena can be explained by the fact that beta-cell specifically expresses the UPE binding protein. Assuming that there may be Box VI-binding protein playing negative roles both in hepatocyte and beta-cell, and that the protein acts as a negative regulator of GLUT2 gene, the UPE binding protein in the beta-cell may overcome the inhibition by binding to the protein.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Protein Binding
/
Binding Sites
/
Monosaccharide Transport Proteins
/
Comparative Study
/
Cell Line
/
Gene Expression Regulation
/
Islets of Langerhans
/
Promoter Regions, Genetic
/
Transcription Factor AP-1
/
DNA Footprinting
Limits:
Animals
Language:
English
Journal:
Experimental & Molecular Medicine
Year:
1998
Type:
Article
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