Structure, expression, and regulation of members of the developmentally controlled V and H gene classes from Dictyostelium.
Structure, expression, and regulation of members of the developmentally controlled V and H gene classes from Dictyostelium.
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DOI：
10.1002/dvg.1020120116
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
C. Singleton;R. Delude;R. Ken;S. Manning;C. McPherson
中科院分区：
文献类型：
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作者：
C. Singleton;R. Delude;R. Ken;S. Manning;C. McPherson
我们研究了属于V和H基因类的营养专一性基因的表达和结构。这两类基因在发育开始时都会因为转录速度的降低而失活。因此，当末端分化的孢子萌发并由此产生的阿米巴返回营养状态时，必须重新激活这些基因。在萌发过程中，V基因类的大多数成员的表达被激活，这与从孢子壳中出现阿米巴是平行的。当蛋白质合成被抑制时，V基因的激活不发生。H基因的激活时间更不均匀，也不平行出现。H基因即使在蛋白质合成受到抑制的情况下也能被激活。V4被发现是唯一对细菌存在有反应的营养特异体基因。当细菌加入到轴向生长的阿米巴中时，V4的表达通过转录激活增加了25-100倍。对相应的基因组克隆进行分离和序列分析，发现V18和V1两个V基因编码核糖体蛋白。启动子分析已经描绘了几个V和H基因表达和调控所需的序列。在所有情况下，表达都是由转录起始点前几百个碱基对内的序列决定的。对于V18和V14，除了参与调控的序列外，还鉴定了一个正的构成元件。最后，根据V和H基因表达和调控的假设模型讨论了所有的特征和发现。
We have examined the expression and structure of vegetative specific genes belonging to the V and H gene classes. Both classes of genes are deactivated at the onset of development by a reduction in the rate of transcription. Thus, the genes must be reactivated when the terminally differentiated spores germinate and the resulting amebae return to the vegetative state. During germination, activation of expression of most members of the V gene class was found to parallel the emergence of amoebae from the spore coats. The activation of the V genes did not occur when protein synthesis was inhibited. The timing of activation of the H genes was more heterogeneous and did not parallel emergence. H gene activation occurred even when protein synthesis was inhibited. V4 was found to be the only vegetative specific gene that was responsive to the presence of bacteria. V4 expression was induced by 25-100 fold via transcriptional activation when bacteria were added to amebae growing axenically. Isolation and sequence analysis of the corresponding genomic clones revealed that two V genes, V18 and V1, encode ribosomal proteins. Promoter analysis has delineated the sequences necessary for expression and regulation for several of the V and H genes. In all cases, expression was determined by sequences within the first several hundred base pairs of the transcription start site. For V18 and V14, a positive constitutive element was identified in addition to the sequences involved in regulation. Finally, all of the characterizations and findings are discussed in terms of postulated models for V and H gene expression and regulation.