Rodríguez-Zapata L C, Hernández-Sotomayor S M
Unidad de Biología Experimental, Centro de Investigación Científica de Yucatán Apdo., México.
Planta. 1998 Jan;204(1):70-7. doi: 10.1007/s004250050231.
Homogenate fractions (soluble and particulate) from transformed roots of Catharanthus roseus (L.) G. Don showed several phosphorylated proteins when incubated with gamma-[32P]ATP. The phosphorylation in the proteins of 55, 40, 25, 18 and 10 kDa in the particulate fraction and 63 kDa in the soluble fraction was resistant to alkali treatment. Several proteins in both fractions gave a positive signal with monoclonal antiphosphotyrosine antibodies. In-situ phosphorylation in both fractions showed several proteins that cross-reacted with the antiphosphotyrosine antibodies. Tyrosine kinase activity was detected using an exogenous substrate RR-SRC, a synthetic peptide derived from the amino acid sequence surrounding the phosphorylation site in pp60src. This activity was inhibited by genistein, a tyrosine kinase inhibitor. These results indicate, for the first time, the presence of protein-tyrosine kinase (EC 2.7.1.112) activity in transformed plant tissues.
将长春花（Catharanthus roseus (L.) G. Don）转化根的匀浆组分（可溶性和颗粒性）与γ-[32P]ATP一起孵育时，显示出几种磷酸化蛋白。颗粒组分中55、40、25、18和10 kDa的蛋白以及可溶性组分中63 kDa的蛋白的磷酸化对碱处理具有抗性。两个组分中的几种蛋白与单克隆抗磷酸酪氨酸抗体产生阳性信号。两个组分中的原位磷酸化显示出几种与抗磷酸酪氨酸抗体发生交叉反应的蛋白。使用外源性底物RR-SRC（一种源自pp60src磷酸化位点周围氨基酸序列的合成肽）检测酪氨酸激酶活性。该活性被酪氨酸激酶抑制剂染料木黄酮抑制。这些结果首次表明在转化的植物组织中存在蛋白酪氨酸激酶（EC 2.7.1.112）活性。
