水稻类受体激酶的近膜区对激酶活性的影响研究

植物基因组中数目众多的类受体激酶在植物的正常生长发育和对外界环境的反应中都具有重要意义。在类受体激酶的跨膜区和激酶结构域之间有一段序列上并不保守的区域，一般为20几个氨基酸，称为近膜区。在动物受体激酶研究中证实，该区域对激酶活性具有调控作用。在前期工作中，本实验室对水稻激酶进行了克隆、表达和自我磷酸化活性分析。为了研究近膜区对植物类受体激酶活性的影响，本实验进一步克隆和表达了缺失近膜区序列的水稻类受体激酶，并进行了自我磷酸化活性分析。结果表明，缺失近膜区对激酶蛋白质的表达没有明显影响，但是对其活性检测发现，17个缺失近膜区的激酶中有14个激酶的活性丧失。这一结果表明在植物类受体激酶中，近膜区对激酶的活性也具有重要影响。

Effects of Juxtamembrane Region on the Autophosohorylation Activity of Rice Receptor-like Kinases

It has been demonstrated that plant receptor-like kinases play important roles in growth and development and environmental stress. Juxtamembrane region, the fragment between transmembrane and kinase domain in receptor-like kinases, spans about 20 amino acids in length, but the sequences are not conserved. It was demonstrated in animal receptor kinases that juxtamembrane region regulates autophosohorylation activity. Rice kinases were cloned and expressed and analyzed autophosphorylation activities in our previous study. To investigate the effect of juxtamembrane region on the autophosohorylation activity of rice receptor-like kinases, truncated kinases without juxtamembrane region were expressed, and their autophosphorylation activities were analyzed. The results showed that, the absence of juxtamembrane region did not affect the expression of kinase proteins, while 14 out of 17 truncted kinases abolished the activity as detected by autophosphorylation, indicate that the juxtamembrane region may play vital role for the regulation of plant receptor-like kinases.