Cappai Laboratory
| Contact: | Professor Roberto Cappai |
|---|---|
| Phone: | +61 3 8344 2556 |
| Fax: | +61 3 8344 4004 |
| Email: | r.cappai@unimelb.edu.au |
The Cappai laboratory studies the molecular, cellular and structural interactions that result in Alzheimer's disease, prion disease, Parkinson's disease and traumatic brain injury. The laborartory is located in the Bio21 Institute, 30 Flemington Rd, Parkville. www.bio21.org
Key research areas are:
ALZHEIMER'S DISEASE (AD):
The key pathological hallmarks of AD are the extracellular amyloid plaques and the intracellular tangles. The principle component of plaques is the amyloid beta peptide (Aβ). The Aβ peptide is derived from the proteolytic cleavage of the amyloid precursor protein (APP). The Aβ peptide is believed to provide the neurotoxic insult that causes the neurodegeneration that leads to AD.
Structure – function studies of the APP-family.
The normal function of APP and the amyloid precursor-like proteins (APLP1 and APLP2) is unknown. The current data suggests they have a role in modulating cellular viability, since reducing the redundancy of the APP-gene family in APP-family double and triple knockout mice can lead to a lethal phenotype. Current studies are using APP-family knockout mice for in vitro cell based assays and in vivo whole animal studies to determine how APP-family expression affects cellular functions.
Complementing the functional work is a structural project to understand the three dimensional structure of the APP molecule either alone or in co-complex with APP-binding proteins. Knowing the structure of APP will provide insights into APP function. The structures will identify targets upon which to develop drugs to modulate APP processing and therefore prevent Aβ generation.
Mechanisms of amyloid toxicity.
The cellular and molecular factors mediating Aβ neurotoxicity remain poorly defined. Cell culture models are being used to identify the molecular targets of Aβ as well as the cellular and subcellular changes that occur following exposure to toxic Aβ. These studies will identify the neurotoxic Aβ species, Aβ receptors and markers of Aβ toxicity. These factors become targets that can be inhibited to prevent neurotoxicity. As well as developing imaging agents to detect the toxic species in AD subjects.
PARKINSON'S DISEASE (PD):
PD is a movement disorder caused by the loss of neurons from the substantia nigra. The key pathological hallmark of PD is the intracellular inclusions called Lewy bodies which are composed mainly of the α-synuclein protein.
Structural properties of α-synuclein.
The α-synuclein protein is a cytoplasmic protein that undergoes a structural transition from an unfolded state into an α-helical containing conformation. We have been studying the factors that modulate this structural change and found that dopamine and lipids can alter the biophysical properties of α-synuclein. Our goal is to relate these in vitro studies to the pathological pathways that occur in PD.
Objectives
- To determine the function of the Alzheimer's disease Amyloid Precursor Protein and how APP binding molecules modulate its function and metabolism.
- To determine the structure of the proteins and protein complexes involved in Alzheimer's and Parkinson's disease.
- To determine the key molecular interactions and cellular pathways that are critical for neurotoxicity and pathology in Alzheimer's and Parkinson's disease.
Major Achievements
- Identifying APP as a modulator of metal homeostasis.
- Identifying dopamine as a modulator of α-synuclein aggregation
- Identifying glypican-1 as a target for the APP:Cu complex.
- Solving the structure of the N-terminal growth factor and copper binding domains of APP.
- Identifying SorLA as a key modulator of APP processing.
Techniques
- Molecular biology
- Cell biology
- Protein expression and purification
- Neurochemistry
- Structural biology - Crystallography and Nuclear Magnetic Resonance
- Biophysical techniques of protein aggregation
Collaborations
Departmental:
Kevin Barnham, Cyril Curtain and Tony White
University:
Andrew Hill (Biochemistry)
External:
National Collaborators
- Corinna van den Huevel, University of Adeliade.
International Collaborators
- Gerd Multhaup, Free University, Berlin, Germany
- Lars-Åke Fransson, Dr Katrin Mani, Lund University, Lund, Sweden
- Olav Andersen, University of Aarhus, Aarhus, Denmark
- K.P Mohanakumar, Indian Institute of Chemical Biology, Kolkata, India
- Sasanka Chakrabarti, Institute of Post-Graduate Medical Education & Research, Kolkata India
- Frédéric Mascarelli, INSERM, Centre de Recherche des Cordeliers, Paris, France
- Fabio Falsone, Institute of Chemistry, University of Graz, Graz, Austria
Funding
- NHMRC Program Grant
- NHMRC Senior Research Fellowship
- ARC Project Grant
Recent Publications
- Corrigan F, Pham CL, Vink R, Blumbergs PC, Masters CL, van den Heuvel C and Cappai R Ther neuroprotective domains of the amyloid precursor protein, in traumatic brain injury, are located in the two growth factor domains. Brain Research (2011) 1378:137-143
- Ciccotosto G.D., Tew D.J., Drew S.C., Smith D.G., Johanssen T., Lal V., Lau T-L., Perez K., Curtain C.C., Wade J.D., Separovic F., Masters C.L., Smith J.P., Barnham K.J. and Cappai R. Stereospecific interactions are necessary for Alzheimer's Disease Amyloid-β toxicity. Neurobiology of Aging (2011) 32: 235-248.
- Dinet V, An N, Ciccotosto GD, Bruban J, Maoui A, Bellingham SA, Hill AF, Andersen OM, Nykjaer A, Jonet L, Cappai R, Mascarelli F. APP involvement in retinogenesis of mice. Acta Neuropathologica (2011) 121:351-363.
- Falsone SF, Kungl AJ, Rek A, Cappai R, Zangger K. The molecular chaperone Hsp90 modulates intermediate steps of amyloid assembly of the Parkinson-related protein alpha-synuclein. Journal of Biological Chemistry (2009) 284:31190-31199
- Leong SL., Pham C.L.L., Galatis D., Fodero-Tavoletti M.T., Perez K., Hill A.F., Masters C.L., Ali F.A., Barnham K.J., and Cappai R. Formation of dopamine-mediated α-synuclein soluble oligomers requires methionine oxidation. Free Radical Biology & Medicine (2009) 460:1328-1337
- Pham C.L.L., Leong SL., Ali F.A., Kenche V.B., Hill A.F., Gras S.L., Barnham K.J., and Cappai R. Dopamine and the dopamine oxidation product 5,6-dihydroxylindole promote distinct on and off-pathway aggregation of α-synuclein in a pH dependent manner. Journal of Molecular Biology (2009) 387: 771–785
- Barnham K.J., Kenche V.B., Ciccotosto G.D., Smith D.P., Tew D.J., Liu X., Perez K., Cranston G.A., Johanssen T.J., Volitakis I., Bush A.I., Masters C.L., White A.R.,, Smith J.P., Cherny R.A and Cappai R. Platinum based inhibitors of amyloid-β as therapeutic agents for Alzheimer’s disease. Proceeding of the National Academy of Sciences (USA) (2008) 105: 6813– 6818
- Needham B.E., Wlodek M.E., Ciccotosto G.D., Fam B.C., Masters C.L., Proietto J, Andrikopoulos S. and Cappai R. Identification of the Alzheimer's disease amyloid precursor protein (APP) and its homolog APLP2 as essential modulators of glucose and insulin homeostasis and growth. Journal of Pathology (2008) 215: 155-163
- Smith D.P., Tew D.J., Hill A.F., Bottomley S.P., Masters C.L., Barnham K.J. and Cappai R. Formation of a high affinity lipid-binding intermediate during the early aggregation phase of α-synuclein. Biochemistry (2008) 47: 1425-1434