Kinesin mRNA Is Present in the Squid Giant Axon |
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Authors: | Anthony E Gioio Jong-Tai Chun Marianna Crispino †Carla Perrone Capano Antonio Giuditta Barry B Kaplan |
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Institution: | Molecular Neurobiology and Genetics Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, U.S.A.;; Dipartimento di Fisiologia Generale e Ambientale, Universita di Napoli, and; Istituto Internazionale di Genetica e Biofisica, Napoli, Italy |
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Abstract: | Abstract: 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 β-actin and β-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. |
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Keywords: | Kinesin cDNA clone Axonal mRNA Giant axon Squid |
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