The lifecycle of the neuronal microtubule transport machinery.

Neurons are incredibly reliant on their cytoskeletal transport machinery. During development the cytoskeleton is the primary driver of growth and remodelling. In mature neurons the cytoskeleton keeps all components in a constant state of movement, allowing both supply of newly synthesized proteins to distal locations as well as the removal of aging proteins and organelles for recycling or degradation. This process is most challenging within axons as large distances need to be covered between synthesis and degradation, but it is essential as the lifetime of any single protein is much shorter than the lifetime of the neuron and its synapses. However, the transport machinery itself also has to be actively transported, recycled and degraded in order to localise properly and perform within neurons. This review provides an overview of the lifecycle of cytoskeletal components in neurons, focusing on its spatial organisation over time in the axon.