Cloning of the human cholesterol 7 alpha-hydroxylase gene (CYP7) and localization to chromosome 8q11-q12.
Cholesterol 7 alpha-hydroxylase (7 alpha-hydroxylase) is a microsomal cytochrome P450 that catalyzes the first step in bile acid synthesis. In this paper, we describe the cloning, characterization, and chromosomal mapping of the human 7 alpha-hydroxylase gene (CYP7). The gene spans 10 kb and contains six exons and five introns. The exon-intron boundaries are completely conserved between the human and rat genes. Sequencing of the 5' flanking region revealed consensus recognition sequences for a number of liver-specific transcription factors. The human CYP7 gene was mapped to chromosome 8q11-q12 using both mouse-human somatic cell hybrids and in situ chromosomal hybridization studies. A total of four single-stranded conformation-dependent DNA polymorphisms and an Alu sequence-related polymorphism were identified. Of the individuals analyzed, 80% were heterozygous for at least one of these five polymorphisms. The localization and characterization of the human 7 alpha-hydroxylase gene, as well as the identification of polymorphisms, provide the molecular tools necessary to investigate the role of this gene in disorders of cholesterol and bile acid metabolism.
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235.
J C
JC
Cohen
J J
JJ
Cali
D F
DF
Jelinek
M
M
Mehrabian
R S
RS
Sparkes
A J
AJ
Lusis
D W
DW
Russell
H H
HH
Hobbs
D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics*; D002874:Chromosome Mapping; D002898:Chromosomes, Human, Pair 8; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D005787:Gene Frequency; D006801:Humans; D006822:Hybrid Cells; D007438:Introns / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010375:Pedigree; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D017385:Sequence Homology
D002790:Cholesterol 7-alpha-Hydroxylase