Semizarov D, Glesne D, Laouar A, Schiebel K, Huberman E
Center for Mechanistic Biology and Biotechnology, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
Proc Natl Acad Sci U S A. 1998 Dec 22;95(26):15412-7. doi: 10.1073/pnas.95.26.15412.
To identify genes involved in macrophage development, we used the differential display technique and compared the gene expression profiles for human myeloid HL-60 leukemia cell lines susceptible and resistant to macrophage maturation. We identified a gene coding for a protein kinase, protein kinase X (PRKX), which was expressed in the maturation-susceptible, but not in the resistant, cell line. The expression of the PRKX gene was found to be induced during monocyte, macrophage, and granulocyte maturation of HL-60 cells. We also studied the expression of the PRKX gene in 12 different human tissues and transformed cell lines and found that, among these tissues and cell types, the PRKX gene is expressed only in blood. Among the blood cell lineages, the PRKX gene is specifically expressed in macrophages and granulocytes. Antisense inhibition of PRKX expression blocked terminal development in both the leukemic HL-60 cells and normal peripheral blood monocytes, implying that PRKX is a key mediator of macrophage and granulocyte maturation. Using the HL-60 cell variant deficient in protein kinase C-beta (PKC-beta) and several stable PKC-beta transfectants, we found that PRKX gene expression is under control of PKC-beta; hence PRKX is likely to act downstream of this PKC isozyme in the same signal transduction pathway leading to macrophage maturation.
为了鉴定参与巨噬细胞发育的基因，我们使用了差异显示技术，比较了对巨噬细胞成熟敏感和抗性的人髓系HL-60白血病细胞系的基因表达谱。我们鉴定出一个编码蛋白激酶的基因，蛋白激酶X（PRKX），它在对成熟敏感的细胞系中表达，而在抗性细胞系中不表达。发现PRKX基因的表达在HL-60细胞的单核细胞、巨噬细胞和粒细胞成熟过程中被诱导。我们还研究了PRKX基因在12种不同人类组织和转化细胞系中的表达，发现在这些组织和细胞类型中，PRKX基因仅在血液中表达。在血细胞谱系中，PRKX基因在巨噬细胞和粒细胞中特异性表达。PRKX表达的反义抑制阻断了白血病HL-60细胞和正常外周血单核细胞的终末发育，这意味着PRKX是巨噬细胞和粒细胞成熟的关键介质。使用缺乏蛋白激酶C-β（PKC-β）的HL-60细胞变体和几种稳定的PKC-β转染子，我们发现PRKX基因的表达受PKC-β的控制；因此，PRKX可能在导致巨噬细胞成熟的同一信号转导途径中在这种PKC同工酶的下游起作用。
