Heterogeneous nuclear ribonucleoprotein K, an RNA-binding protein, is required for optic axon regeneration in Xenopus laevis
| Autor: | Sarah K. Deaton, Hurong Yu, Yuanyuan Liu, Ben G. Szaro |
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| Rok vydání: | 2012 |
| Předmět: |
Male
Gene knockdown Heterogeneous nuclear ribonucleoprotein General Neuroscience RNA-binding protein Optic Nerve Articles Biology Axonogenesis Molecular biology Retinal ganglion Axons Nerve Regeneration Heterogeneous-Nuclear Ribonucleoprotein K Xenopus laevis medicine.anatomical_structure Gene Knockdown Techniques Optic nerve medicine Animals Female Axon RNA Processing Post-Transcriptional Protein Processing Post-Translational |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 32(10) |
| ISSN: | 1529-2401 |
| Popis: | Axotomized optic axons ofXenopus laevis, in contrast to those of mammals, retain their ability to regenerate throughout life. To better understand the molecular basis for this successful regeneration, we focused on the role of an RNA-binding protein, heterogeneous nuclear ribonucleoprotein (hnRNP) K, because it is required for axonogenesis during development and because several of its RNA targets are under strong post-transcriptional control during regeneration. At 11 d after optic nerve crush, hnRNP K underwent significant translocation into the nucleus of retinal ganglion cells (RGCs), indicating that the protein became activated during regeneration. To suppress its expression, we intravitreously injected an antisense Vivo-Morpholino oligonucleotide targeting hnRNP K. In uninjured eyes, it efficiently knocked down hnRNP K expression in only the RGCs, without inducing either an axotomy response or axon degeneration. After optic nerve crush, staining for multiple markers of regenerating axons showed no regrowth of axons beyond the lesion site with hnRNP K knockdown. RGCs nonetheless responded to the injury by increasing expression of multiple growth-associated RNAs and experienced no additional neurodegeneration above that normally seen with optic nerve injury. At the molecular level, hnRNP K knockdown during regeneration inhibited protein, but not mRNA, expression of several known hnRNP K RNA targets (NF-M, GAP-43) by compromising their efficient nuclear transport and disrupting their loading onto polysomes for translation. Our study therefore provides evidence of a novel post-transcriptional regulatory pathway orchestrated by hnRNP K that is essential for successful CNS axon regeneration. |
| Databáze: | OpenAIRE |
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