Romkes M, Faletto M B, Blaisdell J A, Raucy J L, Goldstein J A
Laboratory of Biochemical Risk Analysis, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Biochemistry. 1991 Apr 2;30(13):3247-55. doi: 10.1021/bi00227a012.
The present study characterizes the profile of cDNAs from the human P450IIC subfamily in a library from one individual, and it describes three new members of this subfamily (IIC17, IIC18, and IIC19) isolated from two human cDNA libraries. cDNA libraries were constructed from two human livers which differed phenotypically in the hepatic content of P450 HLx (IIC8). The library from the phenotypically low HLx individual was screened by using a cDNA for rat liver P450IIC13 and an oligonucleotide probe for human IIC8. One clone, 245c, was isolated which clearly represents a new member of the human P450IIC subfamily (IIC17). This clone lacked the first 358 nucleotides at the N-terminus but was only 91% homologous in its nucleic acid sequence to IIC9 and 79% homologous to IIC8. Near-full-length clones for IIC9 were also isolated from this library, but no clones for IIC8 were found. Northern blots indicated that the mRNA for IIC8 was low or absent in this individual. A second cDNA library (from a liver phenotypically high in HLx) was then screened. Eighty-three essentially full-length (greater than 1.8 kb) clones belonging to the IIC subfamily were isolated from this library. These include full-length clones for two additional new members of the IIC subfamily. Clones 29c and 6b appear to be allelic variants (IIC18), differing by one nucleotide (one amino acid change) in the coding region. Clone 11a represents a full-length clone for a third new P450 (IIC19).(ABSTRACT TRUNCATED AT 250 WORDS)
本研究描述了来自一个个体文库中人类P450IIC亚家族的cDNA概况，并介绍了从两个人类cDNA文库中分离出的该亚家族的三个新成员（IIC17、IIC18和IIC19）。cDNA文库是由两个在P450 HLx（IIC8）肝脏含量上表现型不同的人类肝脏构建而成。通过使用大鼠肝脏P450IIC13的cDNA和人类IIC8的寡核苷酸探针，对表现型低HLx个体的文库进行筛选。分离出一个克隆245c，它显然代表人类P450IIC亚家族的一个新成员（IIC17）。该克隆在N端缺少最初的358个核苷酸，但其核酸序列与IIC9的同源性仅为91%，与IIC8的同源性为79%。也从该文库中分离出了IIC9的近全长克隆，但未发现IIC8的克隆。Northern印迹表明该个体中IIC8的mRNA含量低或不存在。然后对第二个cDNA文库（来自HLx表现型高的肝脏）进行筛选。从该文库中分离出83个基本全长（大于1.8 kb）且属于IIC亚家族的克隆。其中包括IIC亚家族另外两个新成员的全长克隆。克隆29c和6b似乎是等位变体（IIC18），在编码区相差一个核苷酸（一个氨基酸变化）。克隆11a代表第三个新P450（IIC19）的全长克隆。（摘要截短于250字）
