Dr Mark Prescott

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Dr Mark Prescott

Lecturer and Research Fellow

Telephone: +61 - 3 9905 3724 Facsimile: +61 - 3 9905 4699 Email: Mark.Prescott@med.monash.edu.au

Research

Structure of pigments isolated from corals

Reef-building corals are renowned for their vivid and diverse colours. The proteins that are responsible for these myriad colours are called pocilloporins and many are fluorescent. They possess multiple photoprotective functions one of which is to protect the photosystems of their resident photosynthetic algae from large light fluctuations. These pigments are related to the green fluorescent protein isolated from the jelly fish Aequorea victoria. We are studying the relationship between the structure, colour and fluorescence properties of the pocilloporins with the aim of contributing to our understanding of their function in vivo.

The pocilloporins represent potential powerful tools for biotechnology. We have recently determined the crystal structure of one member of this family and aim to determine other family members and to engineer new variants with the aim to generate a new array of products for biotechnology use.

Autophagy

Autophagy is a fundamental cellular process. It is involved in the processes of starvation, cell death, development and pathogenesis. In particular autophagy has been linked to degenerative diseases of the nervous system and muscle such as Alzheimer's disease and Danon disease.

Most intracellular short-lived proteins are selectively degraded by the ubiquitin-proteasome pathway while most long-lived proteins are degraded in lysosomes. Autophagy is the process of delivering proteins destined for degradation to the lysosome. One form of autophagy is macroautophagy and is responsible for the majority of intracellular protein degradation including organelles such as the mitochondrion.

The molecular mechanism of autophagy is poorly understood. We are investigating the role of autophagy in development and pathogenesis with a particular focus on the turnover of the mitochondria. We have developed some novel assays based on fluorescent proteins that allow autophagy of specific cellular constituents to be followed in the living cell.

Fluorescence Lifetime Imaging Facility

The structure and function of a molecular machine: mitochondrial ATP synthase (mtATPase)

ATP synthase is responsible for the synthesis of almost all ATP used by cells. We are interested in understanding the structure and function of this enzyme, the smallest known rotary motor. The complex is driven to make ATP on an extrinsic membrane catalytic sector by proton flow through their membrane channel.

Laboratory Co-workers

Paul Gavin Bsc (Hons) Monash University
e-mail: Paul.Gavin@med.monash.edu.au

Szczepan Nowakowski Bsc (Hons) Monash University
email: Szczepan.Nowakowski@med.monash.edu.au

Carlos Rosado Bsc (Hons) Monash University
e-mail: Carlos.Rosado@med.monash.edu.au

Pascal Wilman BSc (Hons), Monash University, PhD student
e-mail: Pascal.Wilmann@med.monash.edu.au

Jans Petersen Visiting scientist: University of Freiburg, Germany
e-mail: jan.petersen@physchem.uni-freiburg.de

Anne Pettikiriarachchi Honours student
e-mail: Anne.Pettikiriarachchi@med.monash.edu.au

Janani Varatharajah Honours student
e-mail: Janani.Varatharajah@med.monash.edu.au

Selected Publications

1. Prescott M, Ling M, Beddoe T, Oakley AJ, Dove S, Hoegh-Guldberg O, Devenish RJ, and Rossjohn J. The 2.2 Å crystal structure of a pocilloporin pigment reveals a nonplanar chromophore conformation. Structure 11, 275-84 (2003).
   
   
2. Gavin P, Devenish RJ, and Prescott M. An approach for reducing unwanted oligomerisation of DsRed fusion proteins. Biochem Biophys Res Commun. 298, 707-13 (2002).
   
   
3. Prescott M, Nowakowski S, Gavin P, Nagley P, Whisstock JC and Devenish RJ. Subunit gamma-green fluorescent protein fusions are functionally incorporated into mitochondrial F1F0-ATP synthase, arguing against a rigid cap structure at the top of F1. J. Biol Chem. 278, 251-6 (2003)
   
   
4. V R, Tan A, Ooms LM, McGrath MJ, Huysmans RD, Munday AD, Prescott M, Whisstock JW, Mitchell CA. Identification of a novel domain in two mammalian inositol polyphosphate 5-phosphatases that mediates membrane ruffle localization: Inositol 5-phosphatase SKIP localizes to the endoplasmic reticulum and translocates to membrane ruffles following EGF stimulation. J. Biol Chem. (2003) in press
   
   
5. Devenish RJ, Prescott M, Roucou X, Nagley P. Insights into ATP synthase assembly and function through the molecular genetic manipulation of subunits of the yeast mitochondrial enzyme complex. Biochim Biophys Acta. 1458, 428-42. (2000) Review.
   
   
6. Bateson, M., Nagley, P., Devenish, R.J., and Prescott, M. Single copies of subunits d, OSCP and b are present in the Saccharomyces cerevisiae mitochondrial ATP synthase. Journal of Biological Chemistry 274, 7462-7466 (1999).