TEMPORAL REGULATION OF LIN-14 BY THE ANTAGONISTIC ACTION OF 2 OTHER HETEROCHRONIC GENES, LIN-4 AND LIN-28
TEMPORAL REGULATION OF LIN-14 BY THE ANTAGONISTIC ACTION OF 2 OTHER HETEROCHRONIC GENES, LIN-4 AND LIN-28
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DOI：
10.1101/gad.5.10.1825
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发表时间：
1991-10-01
影响因子：
10.5
通讯作者：
RUVKUN, G
中科院分区：
文献类型：
--
作者：
ARASU, P;WIGHTMAN, B;RUVKUN, G
异慢性基因形成调控途径，控制秀丽隐杆线虫胚胎后细胞谱系的时间序列。其中一个基因lin-14编码一种核蛋白，这种核蛋白构成了一个时间发育开关。在野生型发育过程中，lin-14蛋白在早期幼虫阶段1 （L1）丰富，以指定L1特异性细胞系，但在L2和后期阶段几乎检测不到，以指定L2特异性和更晚的细胞系。为了确定其他基因在执行这种时间开关中所起的作用，我们分析了其他异时基因如何调节lin-14的表达。在L1阶段，lin-4需要下调lin-14蛋白水平，而lin-28则需要正向调节lin-14蛋白水平。lin-4基因产物是与lin-14 3'-非翻译区负调控元件相互作用的候选基因。Lin-29突变不影响lin-14蛋白水平，这与Lin-29作用于lin-14的下游是一致的。在L1阶段关闭lin-14表达本身不是由时间的流逝触发的，而是通常依赖于喂养或依赖于喂养的胚胎后细胞分裂的启动。
Heterochronic genes form a regulatory pathway that controls the temporal sequence of the Caenorhabditis elegans postembryonic cell lineage. One of these genes, lin-14, encodes a nuclear protein that constitutes a temporal developmental switch. During wild-type development, lin-14 protein is abundant during early larval stage 1 (L1) to specify L1-specific cell lineages but is nearly undetectable at L2 and later stages to specify L2-specific and later cell lineages. To determine the roles played by other genes in executing this temporal switch, we have analyzed how lin-14 expression is regulated by other heterochronic genes. lin-4 is required to down-regulate lin-14 protein levels during the L1 stage, whereas lin-28 positively regulates lin-14 protein levels. The lin-4 gene product is a candidate for interacting with the negative regulatory element in the 3'-untranslated region of lin-14. lin-29 mutations do not affect lin-14 protein levels, consistent with lin-29 acting downstream of lin-14. Switching off lin-14 expression during the L1 stage is not triggered by the passage of time per se but, rather, is normally dependent on feeding or the feeding-dependent initiation of postembryonic cell division.