Visiting researcher at the Marine Biological Laboratory - Woods Hole, MA, USA: characterization of a novel 65 kDa RNA-binding protein in presynaptic terminals of squid (Loligo) neurons

Abstract

The giant synapse and axons of squid (Loligo) represent an important classical model that has contributed to detailed mechanisms of axoplasmic flux and neural transmission. This neuronal system has also played a critical role in the long standing question of whether local mRNA processing and protein synthesis occur at the synapse. It is now known for both mammalian and invertebrate systems, that synapses have an unique assembly of mRNAs and are active in synthesizing proteins. This activity has been associated with receptor activation and functional plasticity. The questions that now arise are what are the exact components and mechanisms involved in these processes and how may they be regulated and related to synaptic activity. Answers to these questions are relevant to our understanding of neurological disease conditions, as well as to the application of stem cell-transplant therapies, currently under intense investigation. We have recently identified a novel 65 kDa RNA-binding protein in the presynaptic terminals of the squid giant synapse and in synaptosomes* from the optic lobe. Our working hypothesis is that this RNA-binding protein is a novel lead into the mechanisms that link local RNA processing with neurotransmission. At the Marine Biological Laboratory (MBL) where we can obtain fresh squid (Loligo pealei) during the period from June to August, we will apply biochemical, immunofluorescence, and immunodetection techniques in our investigation. We expect that our results will provide insights into basic mechanisms involved in synaptic plasticity. *Synaptosomes are isolated nerve terminals prepared from fresh tissue, important for biochemical studies. (AU)