Partanen J, Mäkelä T P, Alitalo R, Lehväslaiho H, Alitalo K
Department of Virology and Pathology, University of Helsinki, Finland.
Proc Natl Acad Sci U S A. 1990 Nov;87(22):8913-7. doi: 10.1073/pnas.87.22.8913.
Tyrosine phosphorylation is important in the transmission of growth and differentiation signals; known tyrosine kinases include several oncoproteins and growth factor receptors. Interestingly, some differentiated cell types, such as erythrocytes and platelets contain high amounts of phosphotyrosine. We analyzed tyrosine kinases expressed in the K-562 chronic myelogenous leukemia cell line, which has a bipotential erythroid and megakaryoblastoid differentiation capacity. Analysis of 359 polymerase chain reaction-amplified cDNA clones led to the identification of 14 different tyrosine kinase-related sequences (JTK1-14). Two of the clones (JTK2 and JTK4) represent unusual members of the fibroblast growth factor receptor gene family, and the clones JTK5, JTK11, and JTK14 may also belong to the family of receptor tyrosine kinases but lack a close relationship to any known tyrosine kinase. Each of these different genes has its own characteristic expression pattern in K-562 cells and several other human tumor cell lines. In addition, the JTK11 and JTK14 mRNAs are induced during the megakaryoblastoid differentiation of K-562 cells. These tyrosine kinases may have a role in the differentiation of megakaryoblasts or in the physiology of platelets.
酪氨酸磷酸化在生长和分化信号的传递中起着重要作用；已知的酪氨酸激酶包括几种癌蛋白和生长因子受体。有趣的是，一些分化的细胞类型，如红细胞和血小板含有大量的磷酸酪氨酸。我们分析了K-562慢性粒细胞白血病细胞系中表达的酪氨酸激酶，该细胞系具有双潜能红系和巨核母细胞样分化能力。对359个聚合酶链反应扩增的cDNA克隆进行分析，鉴定出14个不同的酪氨酸激酶相关序列（JTK1-14）。其中两个克隆（JTK2和JTK4）代表成纤维细胞生长因子受体基因家族的异常成员，克隆JTK5、JTK11和JTK14也可能属于受体酪氨酸激酶家族，但与任何已知的酪氨酸激酶关系不密切。这些不同的基因在K-562细胞和其他几种人类肿瘤细胞系中都有其独特的表达模式。此外，JTK11和JTK14 mRNA在K-562细胞的巨核母细胞样分化过程中被诱导。这些酪氨酸激酶可能在巨核母细胞的分化或血小板的生理过程中发挥作用。
