Mittermann I, Swoboda I, Pierson E, Eller N, Kraft D, Valenta R, Heberle-Bors E
Division of Immunopathology, AKH, University of Vienna, Austria.
Plant Mol Biol. 1995 Jan;27(1):137-46. doi: 10.1007/BF00019185.
Profilin has recently been identified as an actin-binding protein in higher plants. A cDNA coding for tobacco profilin, which shared an average sequence identity of 75% with other plant profilins, was isolated from a tobacco pollen cDNA library by antibody screening. Tobacco profilin was expressed in Escherichia coli and purified by affinity to poly-(L-proline) Sepharose. A rabbit antiserum was raised against recombinant tobacco profilin and used to estimate the amount of profilin expressed in different tobacco tissues. Profilin can be detected in different somatic tissues, but the expression is 50-100 fold higher in mature pollen. Immunofluorescence and confocal laser scanning microscopy showed a homogeneous distribution of profilin in the cytoplasm of in vitro cultured pollen grains and pollen tubes of tobacco whereas some growing pollen tubes were stained more intensively a their tip. A possible role of pollen profilin as a developmentally upregulated microfilament precursor in mature pollen is discussed.
最近，肌动蛋白结合蛋白在高等植物中被鉴定出来。通过抗体筛选，从烟草花粉cDNA文库中分离出了编码烟草肌动蛋白结合蛋白的cDNA，它与其他植物肌动蛋白结合蛋白的平均序列一致性为75%。烟草肌动蛋白结合蛋白在大肠杆菌中表达，并通过与聚（L-脯氨酸）琼脂糖的亲和力进行纯化。制备了针对重组烟草肌动蛋白结合蛋白的兔抗血清，并用于估计不同烟草组织中肌动蛋白结合蛋白的表达量。在不同的体细胞组织中都能检测到肌动蛋白结合蛋白，但在成熟花粉中的表达量要高50-100倍。免疫荧光和共聚焦激光扫描显微镜显示，在体外培养的烟草花粉粒和花粉管的细胞质中，肌动蛋白结合蛋白呈均匀分布，而一些生长中的花粉管在其顶端染色更强烈。本文讨论了花粉肌动蛋白结合蛋白作为成熟花粉中发育上调的微丝前体的可能作用。
