Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, Room BT 110, 3801 University Street, Montreal, Quebec, Canada H3A 2B4.
Biochem Biophys Res Commun. 2011 Jan 21;404(3):816-21. doi: 10.1016/j.bbrc.2010.12.066. Epub 2010 Dec 21.
Aplysia californica is a model organism for determining the molecular basis of memory. In this system identified synaptic changes have been closely linked to behavioral memories. Long-term sensitization and long-term synaptic changes between sensory neurons and motor neurons require both gene expression followed by translational control of the newly expressed mRNAs. One important mechanism for translational control is mediated through the target of rapamycin (TOR) and one mechanism downstream of TOR is the translational control of mRNAs containing a 5' terminal oligopyrimidine tract (5'TOP) sequence in their mRNA transcript. These include all ribosomal proteins, elongation factors and a few other translational regulators. TOR regulation of 5'TOP mRNAs in vertebrates is thought to be due to TOR dependent removal of the translational repression mediated by the 5'TOP sequence. Here, we show that this mechanism is similar in Aplysia, whereby Aplysia 5'TOP mRNAs are repressed under basal conditions and this repression is removed by serotonin in a rapamycin-sensitive manner.
加利福尼亚海兔是一种用于确定记忆分子基础的模式生物。在这个系统中，已经确定的突触变化与行为记忆密切相关。长时程敏感化和感觉神经元与运动神经元之间的长时程突触变化既需要基因表达，也需要新表达的 mRNA 的翻译控制。翻译控制的一个重要机制是通过雷帕霉素靶蛋白（TOR）介导的，而 TOR 的一个下游机制是含有 5'端寡嘧啶序列（5'TOP）的 mRNA 转录物的翻译控制。这些包括所有核糖体蛋白、延伸因子和一些其他翻译调节剂。脊椎动物中 TOR 对 5'TOP mRNA 的调节被认为是由于 TOR 依赖性去除 5'TOP 序列介导的翻译抑制。在这里，我们表明，这种机制在海兔中是相似的，即 Aplysia 5'TOP mRNAs 在基础条件下受到抑制，这种抑制可以通过 5-羟色胺以 rapamycin 敏感的方式被去除。
