Gioio A E, Chun J T, Crispino M, Capano C P, Giuditta A, Kaplan B B
Department of Psychiatry, University of Pittsburgh School of Medicine, Pennsylvania 15213.
J Neurochem. 1994 Jul;63(1):13-8. doi: 10.1046/j.1471-4159.1994.63010013.x.
Recently, we reported the construction of a cDNA library encoding a heterogeneous population of polyadenylated mRNAs present in the squid giant axon. The nucleic acid sequencing of several randomly selected clones led to the identification of cDNAs encoding beta-actin and beta-tubulin, two relatively abundant axonal mRNA species. To continue characterization of this unique mRNA population, the axonal cDNA library was screened with a cDNA probe encoding the carboxy terminus of the squid kinesin heavy chain. The sequencing of several positive clones unambiguously identified axonal kinesin cDNA clones. The axonal localization of kinesin mRNA was subsequently verified by in situ hybridization histochemistry. In addition, the presence of kinesin RNA sequences in the axoplasmic polyribosome fraction was demonstrated using PCR methodology. In contrast to these findings, mRNA encoding the squid sodium channel was not detected in axoplasmic RNA, although these sequences were relatively abundant in the giant fiber lobe. Taken together, these findings demonstrate that kinesin mRNA is a component of a select group of mRNAs present in the squid giant axon, and suggest that kinesin may be synthesized locally in this model invertebrate motor neuron.
最近，我们报道了一个编码鱿鱼巨大轴突中存在的多聚腺苷酸化mRNA异质群体的cDNA文库的构建。对几个随机选择的克隆进行核酸测序，鉴定出了编码β-肌动蛋白和β-微管蛋白的cDNA，这是两种相对丰富的轴突mRNA种类。为了继续对这个独特的mRNA群体进行表征，用编码鱿鱼驱动蛋白重链羧基末端的cDNA探针筛选轴突cDNA文库。对几个阳性克隆进行测序，明确鉴定出轴突驱动蛋白cDNA克隆。随后通过原位杂交组织化学验证了驱动蛋白mRNA的轴突定位。此外，使用PCR方法证明了轴浆多核糖体部分中存在驱动蛋白RNA序列。与这些发现相反，尽管鱿鱼钠通道的mRNA序列在巨纤维叶中相对丰富，但在轴浆RNA中未检测到。综合这些发现表明，驱动蛋白mRNA是鱿鱼巨大轴突中存在的一组特定mRNA的组成部分，并表明驱动蛋白可能在这个模式无脊椎动物运动神经元中局部合成。
