Structure and function of proteins regulating cell growth and differentiation during asexual reproduction of tunicates

被囊类动物无性繁殖过程中细胞生长和分化调节蛋白的结构和功能

基本信息

批准号：
11480221
负责人：
KAWAMURA Kazuo
金额：
$ 3.65万
依托单位：
Kochi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

Budding tunicates possess a remarkable potential of tissue renewal. Interestingly, this renewal is not accomplished by undifferentiated stem cell but by differentiated somatic cells. As soon as budding or regeneration begins, pigmented epithelial cells (atrial epithelium) undergo dedifferentiation, enter cell division cycle and take undifferentiated shape. This kind of morphogenesis that accompanies dedifferentiation and/or transdifferentiation is also known in Cnidaria and Annelida. In contrast with vertebrate stem cell system, we call this as 'primitive' stem cell system. The goal of our project is to disclose structure and function of proteins that regulate cell growth and differentiation of multipotent cells in budding tunicates.First we have looked for genes that are expressed specifically at budding phase by the method of subtraction, differential display and EST analysis. Secondly, spatio-temporal expression of those genes has been examined by means of in situ hybridization and … More immunohistochemistry. Thirdly, in order to elucidate gene functions, recombinant proteins and mutant proteins have been produced and assayed in vitro using tunicate cell lines.In this project, we have cloned eight kinds of budding-specific genes {retinoid X receptor (RXR), aldehyde dehydrogenase (ALDH), serine protease (TRAMP), serine protease inhibitor (SERPIN), lectin (TC14), reverse transcriptase (RT), cytochrome b5 (Cb5), mitochondrial 16S ribosomal RNA (MTlrRNA)}. ALDH is expressed in the epidermis very early during budding or regeneration. It plays a role in biosynthesis of retinoic acid. Then, retinoic acid induces production and excretion of TRAMP and SERPIN that are dedifferentiation factors of the multipotent cells in budding tunicate. TC14 counteracts the dedifferentiation factors, and its activity is canceled with ease by inhibition sugar such as galactose. Cb5 is known to plays a role in fatty acid biosynthesis. In budding tunicates, fatty acids show cell growth-promoting activity. RT is expressed in the multipotent epithelium. As it resembles fruit fly retroposon, gypsy, RT may play a role in rejuvenation of multipotent, but differentiated cells in budding tunicates. Less

萌芽的双束物具有组织更新的显着潜力。有趣的是，这种更新不是通过未分化的干细胞而是通过分化的体细胞来完成的。萌芽或再生开始后，就可以进行猪的上皮细胞（人为上皮）进行去分化，输入细胞分裂周期并进行未分化的形状。这种形态发生在Cnidaria和Annelida中也已知涉及去分化和/或转分化的形态发生。与脊椎动物干细胞系统相反，我们称其为“原始”干细胞系统。我们项目的目的是披露蛋白质的结构和功能，这些蛋白质调节萌芽束缚物中多能细胞的细胞生长和分化的蛋白质。首先，我们寻找的基因通过减法，差异显示和EST分析的方法在出现阶段特别表达。其次，这些基因的时空表达已通过原位杂交和…更加免疫组织化学进行了研究。第三，为了阐明基因的功能，使用迪士仪细胞系在体外产生并测定重组蛋白和突变蛋白。在该项目中，我们克隆了八种芽的特异性基因{类动物X受体（RXR），Aldehyde dehyde dehyddrogen（Aldh），蛋白（alde）（alde）（alde）（alde）（alde）（alde）。讲座（TC14），逆转录酶（RT），细胞色素B5（CB5），线粒体16S核糖体RNA（mtlRRRNA）}。 ALDH在萌芽或再生过程中很早就在表皮中表达。它在视黄酸的生物合成中起作用。然后，视黄酸诱导流浪汉和Serpin的产生和排泄，它们是多能细胞在发芽中的推导因子。 TC14抵消了去分化因子，其活性通过抑制糖（例如半乳糖）轻松取消。众所周知，CB5在脂肪酸生物合成中起作用。在萌芽的双线线中，脂肪酸显示细胞生长的活性。 RT在多元上皮中表达。由于它类似于果蝇逆转录子，吉普赛（Gypsy），RT可能在萌芽膜中的多能修订中发挥作用，但分化的细胞在芽中的分化。较少的