A novel SDS-stable dimer of a heterogeneous nuclear ribonucleoprotein at presynaptic terminals of squid neurons
Lico, Diego T. P.
Lopes, Gabriel S.
Rosa, José C.
Gould, Robert M.
DeGiorgis, Joseph A.
Larson, Roy E.
MetadataShow full item record
The presence of mRNAs in synaptic terminals and their regulated translation are important factors in neuronal communication and plasticity. Heterogeneous nuclear ribonucleoprotein (hnRNP) complexes are involved in the translocation, stability, and subcellular localization of mRNA and the regulation of its translation. Defects in these processes and mutations in components of the hnRNP complexes have been related to the formation of cytoplasmic inclusion bodies and neurodegenerative diseases. Despite much data on mRNA localization and evidence for protein synthesis, as well as the presence of translation machinery, in axons and presynaptic terminals, the identity of RNA-binding proteins involved in RNA transport and function in presynaptic regions is lacking. We previously characterized a strongly basic RNA-binding protein (p65), member of the hnRNP A/B subfamily, in squid presynaptic terminals. Intriguingly, in SDS-PAGE, p65 migrated as a 65 kDa protein, whereas members of the hnRNP A/B family typically have molecular masses ranging from 35 to 42 kDa. In this report we present further biochemical and molecular characterization that shows endogenous p65 to be an SDS-stable dimer composed of ~37 kDa hnRNPA/B-like subunits. We cloned and expressed a recombinant protein corresponding to squid hnRNPA/B-like protein and showed its propensity to aggregate and form SDS-stable dimers in vitro. Our data suggest that this unique hnRNPA/B-like protein co-localizes with synaptic vesicle protein 2 and RNA-binding protein ELAV and thus may serve as a link between local mRNA processing and presynaptic function and regulation.
Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Neuroscience 300 (2015): 381-392, doi:10.1016/j.neuroscience.2015.05.040.
Showing items related by title, author, creator and subject.
Lico, Diego T. P.; Rosa, José C.; DeGiorgis, Joseph A.; de Vasconcelos, E. J. R.; Casaletti, L.; Tauhata, S. B. F.; Baqui, M. M. A.; Fukuda, M.; Moreira, J. E.; Larson, Roy E. (2009-11-09)A polyclonal antibody (C4), raised against the head domain of chicken myosin Va, reacted strongly towards a 65 kDa polypeptide (p65) on western blots of extracts from squid optic lobes but did not recognize the heavy ...
Madsen, Peter T.; Wilson, M.; Johnson, Mark P.; Hanlon, Roger T.; Bocconcelli, Alessandro; Aguilar De Soto, Natacha; Tyack, Peter L. (Inter-Research, 2007-11-27)Squid play an important role in biomass turnover in marine ecosystems and constitute a food source for ~90% of all echolocating toothed whale species. Nonetheless, it has been hypothesized that the soft bodies of squid ...
Squid giant axon contains neurofilament protein mRNA but does not synthesize neurofilament proteins Gainer, Harold; House, Shirley; Kim, Dong Sun; Chin, Hemin; Pant, Harish C. (2016-05-05)When isolated squid giant axons are incubated in radioactive amino acids, abundant newly synthesized proteins are found in the axoplasm. These proteins are translated in the adaxonal Schwann cells and subsequently transferred ...