Neurons trafficking

Andersen, O.M., Schmidt, V., Spoelgen, R., et al. (2006) Molecular dissection of the interaction between amyloid precursor protein and its neuronal trafficking receptor SorLA/LRl 1. Biochemistry, 45, 2618-2628. 

It is the a2A/D-adrenoceptor that predominates in the locus coeruleus and this subtype seems to be responsible for reducing neuronal excitability and transmitter release. Strangely, immunocytochemical studies suggest that most a2c-receptors are intracellular. The explanation for this finding and its functional implications are as yet unknown but it could reflect differences in intracellular trafficking of different receptor subtypes. 

Upon activation, neurons begin trafficking TRPVl to the membrane where the receptors become activated, desensitized and then recycled to the intracellular compartments. Translocation of TRPVl to the cell membrane occurs via SNARE (snapin and synaptotagmin IX)-mediated exocytosis [37]. Broadly speaking, activation involves phosphorylation by protein kinases (most notably, protein kinase A [PKA] and C [PKC]) and desensitization involves de-phosphorylation by phosphatases (e.g. calcineurin) [38]. Among PKC isozymes, PKCp seems to be of particular importance [39]. 

Neurons constitute the most striking example of membrane polarization. A single neuron typically maintains thousands of discrete, functional microdomains, each with a distinctive protein complement, location and lifetime. Synaptic terminals are highly specialized for the vesicle cycling that underlies neurotransmitter release and neurotrophin uptake. The intracellular trafficking of a specialized type of transport vesicles in the presynaptic terminal, known as synaptic vesicles, underlies the ability of neurons to receive, process and transmit information. The axonal plasma membrane is specialized for transmission of the action potential, whereas the plasma... 

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