Coordinate regulation of the spore coat genes in Dictyostelium discoideum.
Coordinate regulation of the spore coat genes in Dictyostelium discoideum.
复制标题
盘基网柄菌孢子外壳基因的协调调控。
DOI：
10.1002/dvg.1020120120
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Loomis,WF
中科院分区：
文献类型：
--
作者：
Fosnaugh,KL;Loomis,WF
编码三种主要孢子外壳蛋白SP60、SP70和SP96的基因的基因组克隆被用来测量在各种条件下允许发育的突变型和野生型细胞中各自mrna的积累。在所有条件下，这些孢子前特异性mrna在时间和数量上都是协调的，表明它们可能受到相同的调控过程。孢子外壳mrna的积累取决于cAMP受体和Gα2蛋白在聚集阶段的功能以及伴随蛋白的合成。当细胞在发育10小时时与聚集体分离并在0.1 mM EDTA中快速振荡时，它们会形成团块，但不会积累任何所测的孢子前特异性rna。然而，如果在这些细胞中加入0.1 rnM的Ca++或20 μM的cAMP，孢子被膜mrna就会积累。较低浓度的Ca++或cAMP都没有影响。这些结果表明，孢子外壳基因的表达通常涉及一个依赖Ca++的过程，但Ca++的需求可以通过添加高浓度的Ca++外源CAMP来克服。在解离细胞中加入50 nM DIF，即使存在cAMP或ca++，也能阻断孢子外壳mrna的积累。将孢子外壳基因的上游区域与另一个编码孢子前特异性蛋白SP29的基因D19进行了比较。与CACCCAC相关的短序列与这些协同调节基因的转录起始位点大致相同。
Genomic clones of the genes coding for the three major spore coat proteins, SP60, SP70, and SP96, were used to measure the accumulation of their respective mRNAs in mutant and wild‐type cells allowed to develop under a variety of conditions. These prespore‐specific mRNAs were found to be both temporally and quantitatively coordinate under all conditions indicating that they may be subject to identical regulatory processes. Accumulation of the spore coat mRNAs is dependent upon the function of both cAMP receptors and Gα2 proteins during the aggregation stage as well as upon concomitant protein synthesis. When cells are dissociated from aggregates at 10 hr of development and rapidly shaken in 0.1 mM EDTA they form clumps but do not accumulate any of the prespore‐specific RNAs assayed. However, if either 0.1 rnM Ca++or 20 μM cAMP is added to these cells, the spore coat mRNAs accumulate. Lower concentrations of either Ca++or cAMP had no effect. These results suggest that expression of the spore coat genes normally involves a Ca++‐dependent process, but the Ca++requirement can be overcome by adding Ca++high concentrations of exogenous CAMP.Addition of 50 nM DIF to dissociated cell blocks the accu‐ mulation of the spore coat mRNAs even when cAMP or Ca++is present. The upstream regions of the spore coat genes were compared to those of another gene, D19, that codes for the prespore‐specific protein SP29. Short sequences related to CACCCAC were found at about the same position relative to the transcriptional start sites of these co‐ ordinately regulated genes.