Deiss L P, Feinstein E, Berissi H, Cohen O, Kimchi A
Department of Molecular Genetics and Virology, Weizmann Institute of Science, Rehovot, Israel.
Genes Dev. 1995 Jan 1;9(1):15-30. doi: 10.1101/gad.9.1.15.
Programmed cell death is often triggered by the interaction of some cytokines with their cell surface receptors. Here, we report that gamma interferon (IFN-gamma) induced in HeLa cells a type of cell death that had cytological characteristics of programmed cell death. In this system we have identified two novel genes whose expression was indispensable for the execution of this type of cell death. The rescue was based on positive growth selection of cells after transfection with antisense cDNA expression libraries. The antisense RNA-mediated inactivation of the two novel genes protected the cells from the IFN-gamma-induced cell death but not from the cytostatic effects of the cytokine or from a necrotic type of cell death. One of those genes (DAP-1) is expressed as a single 2.4-kb mRNA that codes for a basic, proline-rich, 15-kD protein. The second is transcribed into a single 6.3-kb mRNA and codes for a unique 160-kD calmodulin-dependent serine/threonine kinase (DAP kinase) that carries eight ankyrin repeats. The expression levels of the two DAP proteins were selectively reduced by the corresponding antisense RNAs. Altogether, it is suggested that these two novel genes are candidates for positive mediators of programmed cell death that is induced by IFN-gamma.
程序性细胞死亡通常由某些细胞因子与其细胞表面受体的相互作用所触发。在此，我们报道γ干扰素（IFN-γ）在HeLa细胞中诱导出一种具有程序性细胞死亡细胞学特征的细胞死亡类型。在这个系统中，我们鉴定出两个新基因，其表达对于这种细胞死亡类型的发生必不可少。拯救是基于用反义cDNA表达文库转染后对细胞进行阳性生长选择。反义RNA介导的这两个新基因的失活保护细胞免受IFN-γ诱导的细胞死亡，但不能保护细胞免受细胞因子的细胞生长抑制作用或坏死性细胞死亡。其中一个基因（DAP-1）表达为单一的2.4-kb mRNA，编码一种碱性、富含脯氨酸的15-kD蛋白质。另一个基因转录为单一的6.3-kb mRNA，编码一种独特的160-kD钙调蛋白依赖性丝氨酸/苏氨酸激酶（DAP激酶），该激酶带有八个锚蛋白重复序列。两种DAP蛋白的表达水平被相应的反义RNA选择性降低。总之，提示这两个新基因是IFN-γ诱导的程序性细胞死亡的正向介导因子的候选基因。
