부산대학교 도서관

The axonal microtubules (MTs) support long-distance transport of cargoes that are dispatched to distinct cellular subcompartments. Among them, mRNAs are directly transported in membraneless ribonucleoprotein (RNP) granules that, together with ribosomes, can also hitchhike on fast-moving membrane-bound organelles for accurate transport along MTs. These organelles serve as platforms for mRNA translation, thus generating axonal foci of newly synthesized proteins. Local translation along axons not only supports MT network integrity but also modulates the processivity and function of molecular motors to allow proper trafficking of cargoes along MTs. Thus, identifying the mechanisms that coordinate axonal transport with local protein synthesis will shed new light on the processes underlying axon development and maintenance, whose deregulation often contribute to neurological disorders. The long-range transport of mRNA in RNP granules is intimately linked to the MT-transport machinery by recruitment of molecular motors through RNP granule RBPs. RNP transport granules are mainly considered as translationally repressed structures but their high heterogeneity in RBP content or biophysical properties and the detection of translation in stress granules or moving polysomes may reflect various translational states. RNP granules can also be indirectly transported in neurites by their tethering to membrane-bound organelles and mRNAs are translated at the surface of membrane-bound organelles demonstrating other levels of coordination between MT-based transport and translation. The translation machinery is transported along MTs in neurites by molecular motors to sustain local protein synthesis away from the cell soma. Local protein synthesis of MT-transport machinery is essential for the prompt regulation of transport in response to stimulation signals. [ABSTRACT FROM AUTHOR]