Organelle Distribution and Trafficking in Caenorhabditis Elegans Neurons.
Zahler, Sebastian H.
- Abstract: The neuron is the basic unit of the nervous system and is composed of a cell body, dendrites, and a long axon. Neurons send and receive signals at synapses located at the terminus of axons and at various points throughout the dendritic arbor, and those signals are then transmitted through the dendrites and axons. Because most proteins are synthesized in the cell body, proper synaptic tra... read morensmission requires the transport of hundreds of proteins and membrane bound vesicles from the cell body to the synapses and vice versa. Fluctuation in cellular activity requires continuous production and degradation of proteins, resulting in highly dynamic synaptic protein and vesicle concentrations. One example of a protein whose concentration is closely regulated at the synapse is the glutamate neurotransmitter receptor. This receptor is synthesized in the endoplasmic reticulum, processed in the Golgi complex, and transported from the cell body to be integrated into the synaptic plasma membrane. Conversely, once a receptor is targeted for degradation, it is internalized into endosomes, carried to multi-vesicular bodies, and ultimately degraded by lysosomes. Oftentimes, proteins and vesicles must travel large distances (up to one meter in humans) from the cell body to the synapses. Much remains to be learned about these processes, and in my project I focus on how organelles critical for synapse function are distributed and trafficked in neurons. I do so by examining the distribution of organelles involved in the glutamate receptor trafficking pathway and by identifying the role of the kinesin motor KLP-4 in trafficking these organelles.read less