Drosophila Neural Cell Biology
Drosophila, neuronal cell biology, neuromuscular junction, neurodegeneration, membrane traffic
We are interested in signaling processes that regulate neuronal function - both their basic biology, and their relevance to neurodegenerative disease. Of particular interest are the membrane traffic events relevant to these processes, using Drosophila as a model.
Axonal ER and hereditary spastic paraplegia
Axonal ER forms a continuous tubular network reaching from the rest of the ER in the cell body, all the way to presynaptic terminals. Its formation and function are poorly understood, but its organisation is comparable to a “neuron within a neuron”, potentially able to integrate physiological responses throughout the neuron. Is it important? Almost certainly - the motor axon degeneration disease, hereditary spastic paraplegia (HSP) results from mutations affecting several ER-shaping proteins, but their roles in formation and function of axonal ER are not known.
Using Drosophila, we have established roles for a number of HSP proteins in formation of axonal ER, by finding ER abnormalities in mutant axons. These proteins and mutations provide a valuable resource to better understand the mechanism of axon ER formation, as well as the physiological consequences of disrupting its presence or continuity. Current work includes the development of screening methods to identify additional genes and mechanisms for formation of the axonal ER network, analyses of the ER network by light and electron microscopy, and the consequences of ER disruption for the physiology of axons and other organelles that contact ER.
In addition, we are investigating that roles of other spastic paraplegia genes in autophagic membrane traffic and function.
Click here to view Dr Lulu Zhao's video reconstruction of a tubular endoplasmic reticulum network in a Drosophila motor axon
Genetics and bioinformatics of brain circuitry
I am a member of the Virtual Fly Brain consortium, a hub for integration of brain anatomical, expression, phenotypic and genetic data in Drosophila. As the volume of such data increases, there is a need for easy access to it, similar to the ready access to genome data that has developed over recent decades.
The O'Kane group on an outing to Darwin's home, Down House, at their 2016 lab retreat. From left to right: Cahir O'Kane, Lulu Zhao, Belgin Yalçın, Megan Oliva, Juanjo Perez Moreno, Alex Patto. Anood Sohail was away at the time - we missed her!
4 key publications
- Belgin Yalçın, Lu Zhao, Martin Stofanko, Niamh C O'Sullivan, ZiHan Kang, Matthew R Thomas, Sophie Zaessinger, Olivier Blard, Alex L Patto, Valentina Baena, Mark Terasaki, Cahir J. O'Kane (2016) Modeling of axonal endoplasmic reticulum network by spastic paraplegia proteins. BioRxiv preprint 069005 >> Link to paper
- O'Sullivan NC, Jahn TR, Reid E, O'Kane CJ (2012) Reticulon-like-1, the Drosophila ortholog of the Hereditary Spastic Paraplegia gene reticulon 2, is required for organization of endoplasmic reticulum and of distal motor axons. Hum Mol Gen 21:3356-65 >> Link to paper
- Rocha JJ, Korolchuk VI, Robinson IM, O'Kane CJ (2011) A phagocytic route for uptake of double-stranded RNA in RNAi. PLoS One 6(4): e19087 >> Link to paper
- Wang X, Shaw WR, Tsang HT, Reid E, O'Kane CJ (2007) Drosophila spichthyin inhibits BMP signaling and regulates synaptic growth and axonal microtubules. Nat Neurosci 10: 177-85 >> Link to paper
Page updated 15 Nov 2016