Receptors and biosynthesis of peptide plant cell growth factor, phytosulfokine

肽植物细胞生长因子、植物硫因子的受体和生物合成

基本信息

批准号：
12460148
负责人：
SAKAGAMI Youji
金额：
$ 9.02万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

Peptide plant growth factor, phytosulfokine (PSK) discovered by us, has only five amino acid residues and seems to reveal biological activities via receptorfe) on membrane similar manner of mammal growth factors. We proved that there were the PSK specific binding sites on the rice membrane. On this study, we found that these binding sites were having 120 and 160 kD molecular weight by means of photoafflnity label of PSK derivative. These molecules decrease the molecular weight 10 kD by the treatments of glycosidase. These proteins should be the PSK receptor and the purification of these receptors are now under going.Two tyrosine residues in PSK molecule are both sulfated and these sutfation is necessary to impress the biological activities of PSK. The sulfated tyrosine residues in peptide or protein are abundant modification in animals, however in plant, PSK is the first example and only eaxample until now. Therefore, we began to investigate the plant tyrosil protein sulfotransferase (TPST). Referring animal TPSK researches, we extracted and examined the enzyme activities from several kinds of plant cells which produce PSK. Asparagus cultured cell showed most active source of the TPSK. The properties of this TPSK were similar to those of animal TPSK reported except the optimum pH. We used the partial sequence of PSK precursor or its derivatives as the enzyme substrate and the aspartic acid just before the sequence of PSK showed the most important amino acid for the sulfation that was the same to the animal case. We also purified this enzyme approximately 100 folds. We found that the molecular weight of this plant TPSK was 61-62 kD.

我们发现的肽植物生长因子，植物硫代（PSK），只有五个氨基酸残基，似乎可以通过受体揭示生物学活性）在膜上类似的哺乳动物生长因子的方式上。我们证明了稻膜上有PSK特异性结合位点。在这项研究中，我们发现这些结合位点通过PSK衍生物的Photafflnity标记具有120和160 kD的分子量。这些分子通过糖苷酶的处理降低了10 kD的分子量。这些蛋白质应为PSK受体，并且这些受体的纯化现在正在播放。PSK分子中的两个酪氨酸残基既硫化，又需要这些污染物来打动PSK的生物学活性。肽或蛋白质中硫酸化的酪氨酸残基在动物中是丰富的修饰，但是在植物中，PSK是第一个例子，也是迄今为止的Eaxample。因此，我们开始研究酪氨酸蛋白硫代转移酶（TPST）。参考动物TPSK研究，我们从产生PSK的几种植物细胞中提取并检查了酶活性。芦笋培养的细胞显示出最活跃的TPSK来源。该TPSK的特性与报道的动物TPSK的性质相似，但最佳pH除外。我们将PSK前体或其衍生物的部分序列用作酶底物和天冬氨酸，在PSK序列序列之前显示出与动物病例相同的硫酸化最重要的氨基酸。我们还纯化了大约100倍的酶。我们发现该植物TPSK的分子量为61-62 kd。