Reinhard E, Skene J H
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710.
Perspect Dev Neurobiol. 1992;1(1):29-37.
Recent evidence suggests that GAP-43 expression is not restricted to the nervous system, but may also occur outside the neural cell lineage. Two distinct patterns of GAP-43 regulation can therefore be distinguished. The first is the regulation of GAP-43 expression in multiple cell-types, and the second is the gene's temporal modulation within one specific cell-type. The latter type is well documented for neurons, where GAP-43 regulation is regulated in a fashion that is dependent on axon integrity. Results from partial analysis of the GAP-43 promoter/enhancer region indicate that at least some of these aspects of GAP-43 gene regulation may be accounted for by distinct cis-acting elements. For example, the expression of a rat GAP-43 promoter fusion gene in epidermal cells of transgenic zebrafish is dependent on an enhancer element, that is clearly distinct from the minimal neural-specific promoter. Characterization of specific GAP-43 regulatory elements responsible for particular aspects of its regulation may provide insight to signal pathways also utilized by other genes during development. Ultimately, a better understanding of the molecular events during development could help to define more precisely the complex sequences necessary for the establishment of an intact organism.
最近的证据表明，GAP - 43的表达并不局限于神经系统，也可能出现在神经细胞谱系之外。因此，可以区分出两种不同的GAP - 43调控模式。第一种是多种细胞类型中GAP - 43表达的调控，第二种是该基因在一种特定细胞类型内的时间调节。后一种类型在神经元中已有充分记录，其中GAP - 43的调控方式取决于轴突的完整性。对GAP - 43启动子/增强子区域的部分分析结果表明，GAP - 43基因调控的至少某些方面可能由不同的顺式作用元件来解释。例如，大鼠GAP - 43启动子融合基因在转基因斑马鱼表皮细胞中的表达依赖于一个增强子元件，该元件明显不同于最小的神经特异性启动子。负责GAP - 43调控特定方面的特定调控元件的表征，可能有助于深入了解发育过程中其他基因也利用的信号通路。最终，更好地理解发育过程中的分子事件有助于更精确地定义建立一个完整生物体所需的复杂序列。
