Human glycosaminoglycan glucuronyltransferase I gene and a related processed pseudogene: genomic structure, chromosomal mapping and characterization.
Here we describe the characterization of the human glycosaminoglycan glucuronyltransferase I gene (GlcAT-I) and a related pseudogene. The GlcAT-I gene was localized to human chromosome 11q12-q13 by in situ hybridization of metaphase chromosomes. GlcAT-I spanned 7 kb of human genomic DNA and was divided into five exons. Northern blot analysis showed that GlcAT-I exhibited ubiquitous but markedly different expressions in the human tissues examined. The GlcAT-I promoter was approx. 3-fold more active in a melanoma cell line than in a hepatoma cell line, providing evidence for the differential regulation of the gene's expression. Stepwise 5' deletions of the promoter identified a strong enhancer element between -303 and -153 bp that included binding motifs for Ets, CREB (cAMP-response-element-binding protein) and STAT (signal transducers and activators of transcription). Screening of a human genomic library identified one additional distinct genomic clone containing an approx. 1.4 kb sequence region that shared an overall 95.3% nucleotide identity with exons 1-5 of GlcAT-I. However, a lack of intron sequences, as well as the presence of several nucleotide mutations, insertions and deletions that disrupted the potential GlcAT-I reading frame, suggested that the clone contained a processed pseudogene. The pseudogene was localized to chromosome 3. The human genome therefore contains two related GlcAT-I genes that are located on separate chromosomes.
Kitagawa
H
H
Department of Biochemistry, Kobe Pharmaceutical University, Higashinada-ku, Kobe 658-8558, Japan. kitagawa@kobepharma-u.ac.jp
Taoka
M
M
Tone
Y
Y
Sugahara
K
K
D001483:Base Sequence; D001665:Binding Sites; D006528:Carcinoma, Hepatocellular / Q000235:genetics; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D002893:Chromosomes, Human, Pair 3; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D005260:Female; D005796:Genes; D015698:Genomic Library; D014453:Glucuronosyltransferase / Q000235:genetics*; D006025:Glycosaminoglycans / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D007438:Introns; D007621:Karyotyping; D008113:Liver Neoplasms / Q000235:genetics; D008545:Melanoma / Q000235:genetics; D008969:Molecular Sequence Data; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D011544:Pseudogenes; D017384:Sequence Deletion; D014157:Transcription Factors / Q000378:metabolism; D014407:Tumor Cells, Cultured
D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006025:Glycosaminoglycans; D014157:Transcription Factors; C437003:glycosaminoglycan glucuronyltransferase I; D014453:Glucuronosyltransferase