title: Post-transcriptional regulation mediated by specific neurofilament introns in vivo.
abstract: Neurons regulate genes post-transcriptionally to coordinate the supply of cytoskeletal proteins, such as the medium neurofilament (NEFM), with demand for structural materials in response to extracellular cues encountered by developing axons. By using a method for evaluating functionality of cis-regulatory gene elements in vivo through plasmid injection into Xenopus embryos, we discovered that splicing of a specific nefm intron was required for robust transgene expression, regardless of promoter or cell type. Transgenes utilizing the nefm 3'-UTR but substituting other nefm introns expressed little or no protein owing to defects in handling of the messenger (m)RNA as opposed to transcription or splicing. Post-transcriptional events at multiple steps, but mainly during nucleocytoplasmic export, contributed to these varied levels of protein expression. An intron of the β-globin gene was also able to promote expression in a manner identical to that of the nefm intron, implying a more general preference for certain introns in controlling nefm expression. These results expand our knowledge of intron-mediated gene expression to encompass neurofilaments, indicating an additional layer of complexity in the control of a cytoskeletal gene needed for developing and maintaining healthy axons.
authors.affiliation: Department of Biological Sciences and the Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Biological Sciences and the Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA bgs86@albany.edu.
authors.forename: Ben G
authors.initials: BG
authors.lastname: Szaro
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D015870:Gene Expression / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D007438:Introns / Q000235:genetics*; D016900:Neurofilament Proteins / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics; D055544:beta-Globins / Q000235:genetics*
chemical_list: D016900:Neurofilament Proteins; D012333:RNA, Messenger; D055544:beta-Globins; C061195:neurofilament protein M
keywords: Cis-regulatory elements; Intron; Neurofilament; Post-transcriptional regulation; Xenopus laevis