Hepatocyte growth factor activator inhibitor type 2 lacking the first Kunitz-type serine proteinase inhibitor domain is a predominant product in mouse but not in human
Hepatocyte growth factor activator inhibitor type 2 lacking the first Kunitz-type serine proteinase inhibitor domain is a predominant product in mouse but not in human
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DOI：
10.1006/bbrc.1999.0268
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发表时间：
1999-02-24
影响因子：
3.1
通讯作者：
Koono, M
中科院分区：
文献类型：
--
作者：
Itoh, H;Kataoka, H;Koono, M
肝细胞生长因子激活物抑制剂2型（HAI-2）是从人胃癌细胞系MKN 45中分离克隆的一种新的Kunitz型丝氨酸蛋白酶抑制剂。成熟的HAI-2蛋白含有两个Kunitz结构域，第一个结构域主要负责对肝细胞生长因子激活剂（HGFA）的抑制活性。本研究通过对公共表达序列标签（dbEST）数据库的筛选，鉴定了HAI-2的小鼠同源物（mHAI-2）。除了对应于人HAI-2的全长cDNA之外，通过逆转录聚合酶链反应（RT-PCR）从小鼠肾脏获得较短尺寸的mHAI-2 cDNA。序列分析表明，该基因编码的第一个Kunitz结构域被完全删除。对小鼠基因组DNA的分析表明，缺失的cDNA是通过选择性剪接机制产生的。令人惊讶的是，缺少第一Kunitz结构域的剪接形式在测试的小鼠的所有组织中是主要的转录物，但在通过RT-PCR分析评估的人的组织中不是。使用抗人HAI-2蛋白的特异性抗血清通过Western印迹分析也证实了这一现象。这些结果表明，在小鼠的各种组织中表达的大多数HAI-2可能不能有效地抑制HGFA，（C）1999 Academic Press.
Hepatocyte growth factor activator inhibitor type 2 (HAI-2) is a new Kunitz-type serine protease inhibitor, which is purified and cloned from human stomach cancer cell line MKN45. The mature HAI-2 protein contains two Kunitz domains and the first domain is mainly responsible for the inhibitory activity against hepatocyte growth factor activator (HGFA). In this study, we identified the mouse homolog of HAI-2 (mHAI-2) by screening the data base of public expressed sequence tag (dbEST). In addition to a full-length cDNA corresponding to human HAI-2, a shorter size of mHAI-2 cDNA was obtained from mouse kidney by reverse-transcription polymerase chain reaction (RT-PCR). Sequence analysis of this shorter cDNA revealed that the region encoding the first Kunitz domain was completely deleted. Analysis of mouse genomic DNA showed that the deleted cDNA was generated by an alternative splicing mechanism. Surprisingly, the spliced form lacking the first Kunitz domain was a predominant transcript in all tissues of mice tested but not in those of human as assessed by RT-PCR analysis. This phenomenon is also confirmed by Western blot analysis using the specific antiserum against human HAI-2 protein. These results suggest that most of HAI-2 expressed in various tissues of mice may be unable to inhibit HGFA efficiently, (C) 1999 Academic Press.