Wolffe A P
Laboratory of Molecular Embryology, National Institute of Child Health and Human Development, Bethesda, Maryland 20892-5431, USA.
J Exp Zool. 1998;282(1-2):239-44.
Chromatin contains DNA, the transcriptional machinery, and structural proteins such as histones. All these components together are necessary for the physiologic control of transcription. A consideration of recent advances leads to a packaging principle for gene regulation. This packaging principle states that the transcriptional activity of a gene is largely controlled by the packaging of the template within chromatin. This assumption follows from experiments that establish the covalent modification of chromatin as a major causal influence on gene activity. DNA methylation and histone acetylation alter the nucleosomal infrastructure to repress or activate transcription. These covalent modifications can have roles in both promoter-specific events and the global control of chromosomal activity. These regulatory functions are essential for vertebrate development.
染色质包含DNA、转录机制以及诸如组蛋白等结构蛋白。所有这些成分共同对于转录的生理控制是必需的。对近期进展的思考引出了一种基因调控的包装原理。该包装原理指出，基因的转录活性在很大程度上由染色质内模板的包装所控制。这一假设源于那些将染色质的共价修饰确立为对基因活性有主要因果影响的实验。DNA甲基化和组蛋白乙酰化改变核小体结构以抑制或激活转录。这些共价修饰在启动子特异性事件和染色体活性的全局控制中都可能起作用。这些调控功能对于脊椎动物的发育至关重要。
