Dorow D S, Devereux L, Dietzsch E, De Kretser T
Peter MacCallum Cancer Institute, Melbourne, Australia.
Eur J Biochem. 1993 Apr 15;213(2):701-10. doi: 10.1111/j.1432-1033.1993.tb17810.x.
Using the polymerase chain reaction to study mRNA expressed in human epithelial tumor cells, a member of a new family of protein kinases was identified. The catalytic domain of this kinase has amino-acid-sequence similarity to both the Tyr-specific and the Ser/Thr-specific kinase classes. Clones representing two members of this new family have been isolated from a human colonic epithelial cDNA library and sequenced. The predicted amino-acid sequences of these clones reveal that, in addition to the unusual nature of their kinase catalytic domains, they contain two Leu/Ile-zipper motifs and a basic sequence, near their C-termini. As they possess domains associated with proteins from two distinct functional groups, these kinases have been named mixed-lineage kinases (MLK) 1 and 2. mRNA from MLK1 has been found to be expressed in epithelial tumor cell lines of colonic, breast and esophageal origin. The MLK1 gene has been mapped to human chromosome 14q24.3-31.
利用聚合酶链反应研究人类上皮肿瘤细胞中表达的信使核糖核酸（mRNA）时，鉴定出了一个新的蛋白激酶家族的成员。该激酶的催化结构域在氨基酸序列上与酪氨酸特异性激酶类和丝氨酸/苏氨酸特异性激酶类均有相似性。已从人类结肠上皮cDNA文库中分离出代表这个新家族两个成员的克隆并进行了测序。这些克隆的预测氨基酸序列显示，除了其激酶催化结构域的非同寻常性质外，它们在靠近C末端处还含有两个亮氨酸/异亮氨酸拉链基序和一个碱性序列。由于它们拥有与来自两个不同功能组的蛋白质相关的结构域，这些激酶被命名为混合谱系激酶（MLK）1和2。已发现来自MLK1的mRNA在结肠、乳腺和食管来源的上皮肿瘤细胞系中表达。MLK1基因已被定位到人类染色体14q24.3 - 31。
