Analysis of the human lumican gene promoter.
The human lumican gene was shown to possess one major transcription start site, resulting in exon 1 of the gene giving rise to the first 74 base pairs (bp) of the 5'-untranslated region. About 1.6 kilobase pairs of upstream promoter sequence were sequenced and analyzed to identify elements responsible for gene expression. No typical TATAA sequence was identified in the vacinity of the transcription start site, but an atypical TATCA sequence residing 41 bp upstream was shown to be necessary for transcription, although it was incapable of supporting transcription by itself. A GC box residing 74 bp upstream of the transcription start site also was essential for the initiation of transcription. Sp3 was identified as the transcriptional activator binding to the GC box. No additional elements that significantly modulated transcription were noted in the promoter sequence analyzed, when using human adult chondrocytes as the cell source for transfection in reporter assays. In contrast, reporter assays carried out in human fetal lung fibroblasts, where lumican expression is deplete, revealed the presence of a repressor element located between 384 and 598 bp upstream of the transcription start site. A GATA-binding site located between bp -386 and -391 was identified as being necessary for repression of transcription. The mouse lumican promoter does not possess an equivalent site, and this may explain why the lumican gene is expressed in fetal murine cartilage but not in fetal human cartilage.
Grover
J
J
Genetics Unit, Shriners Hospital for Children and Department of Surgery, McGill University, Montreal, Quebec H3G 1A6, Canada.
Liu
C Y
CY
Kao
W W
WW
Roughley
P J
PJ
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D016326:Extracellular Matrix Proteins / Q000235:genetics; D050989:GATA2 Transcription Factor; D006023:Glycoproteins / Q000235:genetics; D006801:Humans; D007632:Keratan Sulfate / Q000235:genetics*; D000071234:Lumican; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D016385:TATA Box; D014157:Transcription Factors / Q000378:metabolism
D011508:Chondroitin Sulfate Proteoglycans; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D016326:Extracellular Matrix Proteins; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; C494712:Gata2 protein, mouse; D006023:Glycoproteins; C000604306:LUM protein, human; C000604307:Lum protein, mouse; D000071234:Lumican; C096382:PRELP protein, human; C490748:Prelp protein, mouse; D014157:Transcription Factors; D007632:Keratan Sulfate