Yousef G M, Diamandis E P
Department of Pathology, Mount Sinai Hospital, Toronto M5G 1X5, Toronto, Ontario M5G 1L5, Canada.
J Biol Chem. 1999 Dec 31;274(53):37511-6. doi: 10.1074/jbc.274.53.37511.
Since in rodents the kallikreins are represented by a large multi-gene family, the restriction of this family in humans to three genes is somewhat surprising. In an effort to identify new human kallikrein genes, we examined a genomic area of about 300 kilobases on chromosome 19q13.3-q13.4, a region that contains most of the currently known kallikreins. By using the positional candidate approach, we were able to identify a new gene named KLK-L2 (for kallikrein- like gene 2). Screening of human EST libraries allowed us to delineate the full genomic and cDNA structure of the new gene. KLK-L2 consists of 5 coding exons and 4 introns and has significant similarities to other members of the kallikrein multi-gene family. Homology studies suggest that the protein is likely secreted. KLK-L2 is expressed mainly in breast, brain, and testis and to a lesser extent in many other tissues. KLK-L2 is up-regulated by estrogens and progestins in the breast cancer cell line BT-474.
由于在啮齿动物中激肽释放酶由一个庞大的多基因家族所代表，而该家族在人类中仅包含三个基因，这多少有些令人惊讶。为了鉴定新的人类激肽释放酶基因，我们检测了19号染色体q13.3 - q13.4区域约300千碱基的基因组区域，该区域包含了目前已知的大多数激肽释放酶。通过使用定位候选基因方法，我们成功鉴定出一个名为KLK - L2（激肽释放酶样基因2）的新基因。对人类EST文库的筛选使我们能够描绘出该新基因完整的基因组和cDNA结构。KLK - L2由5个编码外显子和4个内含子组成，与激肽释放酶多基因家族的其他成员具有显著相似性。同源性研究表明该蛋白可能是分泌型的。KLK - L2主要在乳腺、脑和睾丸中表达，在许多其他组织中的表达程度较低。在乳腺癌细胞系BT - 474中，雌激素和孕激素可上调KLK - L2的表达。
