ACTIVATION OF THE PRESPORE AND SPORE CELL PATHWAY OF DICTYOSTELIUM DIFFERENTIATION BY CAMP-DEPENDENT PROTEIN-KINASE AND EVIDENCE FOR ITS UPSTREAM REGULATION BY AMMONIA
ACTIVATION OF THE PRESPORE AND SPORE CELL PATHWAY OF DICTYOSTELIUM DIFFERENTIATION BY CAMP-DEPENDENT PROTEIN-KINASE AND EVIDENCE FOR ITS UPSTREAM REGULATION BY AMMONIA
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DOI：
10.1002/j.1460-2075.1993.tb05900.x
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发表时间：
1993-06-01
期刊：
影响因子：
11.4
通讯作者：
WILLIAMS, JG
中科院分区：
文献类型：
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作者：
HOPPER, NA;HARWOOD, AJ;WILLIAMS, JG
前孢子细胞中盘基网柄菌 cAMP 依赖性蛋白激酶的主要抑制剂的表达阻止其分化为孢子细胞。所得结构包括支撑大量细胞的正常茎，这些细胞不能表达孢子形成特异性基因，并且显示出几种前孢子特异性基因的表达水平大大降低。后一个结果表明，除了激活孢子形成之外，cAMP 依赖性蛋白激酶可能在初始前孢子细胞分化中发挥作用。表达显性抑制剂的菌株的发育对氨的抑制作用高度敏感，氨分子被认为在正常发育过程中抑制进入顶峰。这一结果支持了这样一种模型，即达到最高时环境氨浓度的降低会升高细胞内 cAMP，从而诱导终末分化。
Expression of a dominant inhibitor of the Dictyostelium cAMP-dependent protein kinase in prespore cells blocks their differentiation into spore cells. The resultant structures comprise a normal stalk supporting a bolus of cells that fail to express a sporulation-specific gene and that show greatly reduced levels of expression of several prespore-specific genes. The latter result suggests that in addition to activating spore formation, the cAMP-dependent protein kinase may play a role in initial prespore cell differentiation. Development of the strain expressing the dominant inhibitor is hypersensitive to the inhibitory effects of ammonia, the molecule that is believed to repress entry into culmination during normal development. This result supports a model whereby a decrease in ambient ammonia concentration at culmination acts to elevate intracellular cAMP and hence induce terminal differentiation.