Experimental studies in flies, mice, and humans suggest a significant role of impaired axonal transport in the pathogenesis of Alzheimer's disease (AD). The mechanisms underlying these impairments in axonal transport, however, remain poorly understood. Here we report that the Swedish familial AD mutation causes a standstill of the amyloid precursor protein (APP) in the axons at the expense of its reduced anterograde transport. The standstill reflects the perturbed directionality of the axonal transport of APP, which spends significantly more time traveling in the retrograde direction. This ineffective movement is accompanied by an enhanced association of dynactin-1 with APP, which suggests that reduced anterograde transport of APP is the result of enhanced activation of the retrograde molecular motor dynein by dynactin-1. The impact of the Swedish mutation on axonal transport is not limited to the APP vesicles since it also reverses the directionality of a subset of early endosomes, which become enlarged and aberrantly accumulate in distal locations. In addition, it also reduces the trafficking of lysosomes due to their less effective retrograde movement. Altogether, our experiments suggest a pivotal involvement of retrograde molecular motors and transport in the mechanisms underlying impaired axonal transport in AD and reveal significantly more widespread derangement of axonal transport pathways in the pathogenesis of AD.

• MeSH
• Alzheimerova nemoc * metabolismus   genetika   patologie   MeSH
• amyloidový prekurzorový protein beta * genetika   metabolismus   MeSH
• axonální transport * genetika   MeSH
• axony metabolismus   patologie   MeSH
• dynaktinový komplex metabolismus   genetika   MeSH
• dyneiny metabolismus   MeSH
• endozomy metabolismus   genetika   MeSH
• genetická variace MeSH
• lidé MeSH
• lyzozomy metabolismus   MeSH
• mutace MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nucleolin is a multifunctional RNA Binding Protein (RBP) with diverse subcellular localizations, including the nucleolus in all eukaryotic cells, the plasma membrane in tumor cells, and the axon in neurons. Here we show that the glycine arginine rich (GAR) domain of nucleolin drives subcellular localization via protein-protein interactions with a kinesin light chain. In addition, GAR sequences mediate plasma membrane interactions of nucleolin. Both these modalities are in addition to the already reported involvement of the GAR domain in liquid-liquid phase separation in the nucleolus. Nucleolin transport to axons requires the GAR domain, and heterozygous GAR deletion mice reveal reduced axonal localization of nucleolin cargo mRNAs and enhanced sensory neuron growth. Thus, the GAR domain governs axonal transport of a growth controlling RNA-RBP complex in neurons, and is a versatile localization determinant for different subcellular compartments. Localization determination by GAR domains may explain why GAR mutants in diverse RBPs are associated with neurodegenerative disease.

• MeSH
• axonální transport genetika   MeSH
• buněčné jadérko metabolismus   ultrastruktura   MeSH
• exprese genu MeSH
• fosfoproteiny chemie   genetika   metabolismus   MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• kineziny genetika   metabolismus   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mutace MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nervus ischiadicus cytologie   metabolismus   MeSH
• neurony cytologie   metabolismus   MeSH
• primární buněčná kultura MeSH
• proteinové domény MeSH
• proteiny vázající RNA chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• spinální ganglia cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Central nervous system (CNS) axons lose their intrinsic ability to regenerate upon maturity, whereas peripheral nervous system (PNS) axons do not. A key difference between these neuronal types is their ability to transport integrins into axons. Integrins can mediate PNS regeneration, but are excluded from adult CNS axons along with their Rab11 carriers. We reasoned that exclusion of the contents of Rab11 vesicles including integrins might contribute to the intrinsic inability of CNS neurons to regenerate, and investigated this by performing laser axotomy. We identify a novel regulator of selective axon transport and regeneration, the ARF6 guanine-nucleotide-exchange factor (GEF) EFA6 (also known as PSD). EFA6 exerts its effects from a location within the axon initial segment (AIS). EFA6 does not localise at the AIS in dorsal root ganglion (DRG) axons, and in these neurons, ARF6 activation is counteracted by an ARF GTPase-activating protein (GAP), which is absent from the CNS, ACAP1. Depleting EFA6 from cortical neurons permits endosomal integrin transport and enhances regeneration, whereas overexpressing EFA6 prevents DRG regeneration. Our results demonstrate that ARF6 is an intrinsic regulator of regenerative capacity, implicating EFA6 as a focal molecule linking the AIS, signalling and transport.This article has an associated First Person interview with the first author of the paper.

• MeSH
• alfa řetězce integrinu genetika   metabolismus   MeSH
• amyloidový prekurzorový protein beta genetika   metabolismus   MeSH
• axonální transport genetika   MeSH
• dendrity metabolismus   ultrastruktura   MeSH
• embryo savčí MeSH
• iniciální segment axonu metabolismus   ultrastruktura   MeSH
• krysa rodu rattus MeSH
• malá interferující RNA genetika   metabolismus   MeSH
• mikrotubuly MeSH
• mozková kůra metabolismus   ultrastruktura   MeSH
• neurony metabolismus   ultrastruktura   MeSH
• potkani Sprague-Dawley MeSH
• primární buněčná kultura MeSH
• proteiny aktivující GTPasu genetika   metabolismus   MeSH
• rab proteiny vázající GTP genetika   metabolismus   MeSH
• signální transdukce MeSH
• spinální ganglia metabolismus   ultrastruktura   MeSH
• výměnné faktory guaninnukleotidů antagonisté a inhibitory   genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH