SYNTHESIS AND FUNCTION OF A TRANSFORMATION-DEPENDENT SECRETED LYSOSOMAL PROTEASE

经恶性转化或处理的培养小鼠成纤维细胞 与TPA或生长因子如PDGF合成和分泌39，000 组织蛋白酶L的前体（也称为MEP，主要排泄蛋白） 数量很大组织蛋白酶L是一种活性酸性蛋白酶， 是糖基化的。转化，TPA和PDGF刺激转录 组织蛋白酶L我们已经从小鼠中克隆了一个功能性的组织蛋白酶原L基因， 并鉴定和测序了5'侧翼区，该区域作为 CAT构建体中的启动子。调控转录需要序列 在与上游启动子协同作用的前两个外显子和内含子中， 元素还克隆了人组织蛋白酶原L cDNA并进行了序列测定。一 重组人组织蛋白酶原L的活性研究 细菌表明，无论是“亲”和羧基末端的一部分， 蛋白质需要充分的活动。“亲”的部分似乎是 参与酶的正确折叠，而羧基末端片段 半胱氨酸对活性也是必不可少的，大概是因为它允许 与催化大亚基形成二硫桥。 抗人组织蛋白酶L的多克隆和单克隆抗体已被发现。 使用重组人抗原制备。利用人类的组织蛋白原 L cDNA探针，我们已经证明在所有的人类组织中有组织蛋白酶原L mRNA的表达。 检测的组织和细胞系，在肾癌中表达增加 和肺鳞状细胞癌。

Cultured mouse fibroblasts which are malignantly transformed or treated with TPA or growth factors such as PDGF synthesize and secrete the 39,000 Mr precursor to cathepsin L (also called MEP, for major excreted protein) in large amounts. Cathepsin L is an active acid protease whether or not it is glycosylated. Transformation, TPA and PDGF stimulate transcription of cathepsin L. we have cloned a functional procathepsin L gene from the mouse and have identified and sequenced the 5' flanking region which acts as a promoter in CAT constructions. Regulated transcription requires sequences in the first two exons and introns acting in concert with upstream promoter elements. A human procathepsin L cDNA has also been cloned and sequenced. A study of the activity of recombinant human procathepsin L produced in bacteria indicates that both the "pro" and the carboxy-terminal part of the protein are needed for full activity. The "pro" piece appears to be involved in proper folding of the enzyme, while a carboxyterminal segment cysteine is also essential for activity, presumably because it allows formation of a disulfide bridge with the large catalytic subunit. Polyclonal and monoclonal antibodies to human cathepsin L have been prepared using the recombinant human antigen. Using the human procathepsin L cDNA probe, we have shown expression of procathepsin L mRNA in all human tissues and cell lines tested, with increased expression in renal cancer and squamous cell carcinoma of the lung.