Binding of a pancreatic nuclear protein is correlated with amylase enhancer activity.
The mouse amylase gene Amy-2.2 is expressed at high levels specifically in the acinar cells of the pancreas. The region between -172 and -110 of this gene includes sequence elements common to pancreas-specific genes. Nuclear proteins with specific affinity for this region were partially purified from rat pancreas. The consensus element of another pancreas-specific gene, elastase 1, competes for protein binding to the amylase sequences. Binding was localized by DNase I protection to the sequence -156 to -122. Site-directed mutagenesis of this sequence resulted in concomitant loss of protein binding and enhancer activity. Photo-affinity labelling of pancreatic nuclear extracts identified one predominant binding protein with a molecular weight of approximately 75 kDa. The data indicate that binding of this nuclear protein is essential for the enhancer activity of this pancreas-specific element.
Howard
G
G
Department of Human Genetics, University of Michigan Medical School, Ann Arbor 48109-0618.
Keller
P R
PR
Johnson
T M
TM
Meisler
M H
MH
D000681:Amylases / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004742:Enhancer Elements, Genetic; D005796:Genes; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D010179:Pancreas / Q000201:enzymology*
D009687:Nuclear Proteins; D000681:Amylases