Onodera H, Kobari K, Sakuma M, Sato M, Suyemitsu T, Yamasu K
Department of Regulation Biology, Faculty of Science, Saitama University, Urawa, Japan.
Dev Growth Differ. 1999 Feb;41(1):19-28. doi: 10.1046/j.1440-169x.1999.00405.x.
By screening a cDNA library and 3'-rapid amplification of cDNA ends, the cDNA for a non-receptor type protein tyrosine kinase from the sea urchin Anthocidaris crassispina was analyzed. The deduced protein (AcSrc1) with the highest identity of about 60% to mammalian Src family kinases shows the characteristic features of the Src family. AcSrc1 mRNA is maternally expressed in unfertilized eggs, while zygotic expression is first detected in blastulae and continues through the pluteus stage. Zygotic mRNA expression, visualized by in situ hybridization, is detected specifically in archenteron at the gastrula stage, while it is restricted in plutei to the midgut and hindgut, suggesting specific roles for AcSrcl in the formation and/or functions of the digestive tract. Meanwhile, western blot analysis has shown that the AcSrc1 protein is constantly expressed throughout embryogenesis. By immunostaining, it was found that the protein (distributed evenly in the cytoplasm of unfertilized eggs) is translocated to the membrane after fertilization. All through the following development, AcSrcl was localized to the peripheries of different embryonic cells, although at a relatively low level of localization at the boundaries between adjacent cells.
通过筛选cDNA文库和3'-cDNA末端快速扩增，对来自厚刺海胆（Anthocidaris crassispina）的一种非受体型蛋白酪氨酸激酶的cDNA进行了分析。推导的蛋白（AcSrc1）与哺乳动物Src家族激酶的最高同源性约为60%，显示出Src家族的特征。AcSrc1 mRNA在未受精卵中由母体表达，而合子表达首先在囊胚中检测到，并持续到长腕幼虫阶段。通过原位杂交观察到，合子mRNA表达在原肠胚阶段在原肠中特异性检测到，而在长腕幼虫中则局限于中肠和后肠，这表明AcSrcl在消化道的形成和/或功能中具有特定作用。同时，蛋白质印迹分析表明AcSrc1蛋白在整个胚胎发育过程中持续表达。通过免疫染色发现，该蛋白（在未受精卵的细胞质中均匀分布）在受精后转移到细胞膜上。在随后的整个发育过程中，AcSrcl定位于不同胚胎细胞的周边，尽管在相邻细胞之间的边界处定位水平相对较低。
