Pasquale E B, Singer S J
Department of Biology, University of California, San Diego, La Jolla 92093.
Proc Natl Acad Sci U S A. 1989 Jul;86(14):5449-53. doi: 10.1073/pnas.86.14.5449.
To identify the protein-tyrosine kinases that are expressed during chicken embryonic development, a 10-day chicken embryo cDNA expression library was screened with anti-phosphotyrosine antibodies. Of the positive clones isolated, many encoded the same protein-tyrosine kinase, which we designate Cek1 (chicken embryo kinase 1). Its amino acid sequence suggests that the Cek1 protein is a transmembrane tyrosine kinase and presumably the receptor for an unknown ligand. Antibodies prepared to the cloned Cek1 kinase recognize, in immunoblotting experiments, two protein bands with apparent molecular weights of 100,000 and 110,000. The Cek1 protein was detected in many chicken embryonic tissues, but not in the corresponding adult tissues (with the exception of brain). The Cek1 kinase appears to be very closely related to two protein-tyrosine kinases whose partial sequences have been recently determined, human Flg and mouse Bek. Cloning using anti-phosphotyrosine antibodies has allowed us to detect, in addition to Cek1, several other protein-tyrosine kinases that are expressed during chicken embryonic development, some of which have not been previously identified.
为了鉴定在鸡胚胎发育过程中表达的蛋白酪氨酸激酶，用抗磷酸酪氨酸抗体筛选了一个10日龄鸡胚胎的cDNA表达文库。在分离得到的阳性克隆中，许多编码相同的蛋白酪氨酸激酶，我们将其命名为Cek1（鸡胚胎激酶1）。其氨基酸序列表明Cek1蛋白是一种跨膜酪氨酸激酶，可能是一种未知配体的受体。在免疫印迹实验中，针对克隆的Cek1激酶制备的抗体识别出两条表观分子量分别为100,000和110,000的蛋白条带。在许多鸡胚胎组织中检测到了Cek1蛋白，但在相应的成体组织中未检测到（脑除外）。Cek1激酶似乎与最近已确定部分序列的两种蛋白酪氨酸激酶——人Flg和小鼠Bek密切相关。利用抗磷酸酪氨酸抗体进行克隆，使我们除了检测到Cek1外，还检测到了在鸡胚胎发育过程中表达的其他几种蛋白酪氨酸激酶，其中一些此前尚未被鉴定。
