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A novel 65 kDa RNA-binding protein in squid presynaptic terminals
D T P Lico1, J C Rosa, J A DeGiorgis
1Department of Cellular & Molecular Biology, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil.
Neuroscience
|December 17, 2009
Summary
Researchers identified a novel RNA-binding protein, p65, in squid optic lobes. This protein, a heterogeneous nuclear ribonucleoprotein (hnRNP), is localized to presynaptic terminals and may play a role in synaptic RNA localization.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Myosin V is crucial for intracellular transport.
- Identifying novel proteins involved in neuronal function is essential.
Purpose of the Study:
- To identify and characterize a 65 kDa polypeptide (p65) recognized by an antibody against chicken myosin Va in squid optic lobes.
- To determine the function and localization of p65 within squid neurons.
Main Methods:
- Western blotting using polyclonal antibody C4.
- Purification of p65 via chromatography.
- Mass spectrometry and BLAST analysis for protein identification.
- Sucrose gradient centrifugation and RNase treatment.
- Immunohistochemistry and immunofluorescence microscopy.
Main Results:
- Antibody C4 recognized a 65 kDa polypeptide (p65) in squid optic lobe extracts, distinct from squid myosin V.
- Mass spectrometry and sequence analysis identified p65 as belonging to the heterogeneous nuclear ribonucleoprotein (hnRNP) A/B family.
- p65 associates with cytoplasmic RNP complexes in an RNA-dependent manner.
- Immunolocalization studies revealed p65 is present at presynaptic terminals in the optic lobes and stellate ganglion.
Conclusions:
- p65 is a novel RNA-binding protein found in squid presynaptic terminals.
- p65 likely plays a role in the synaptic localization, translation, or processing of RNA within neurons.
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