Honorary Staff - Dr Adrienne Grant
|Phone:||+61 2 9351 4488|
|Fax:||+61 2 9351 4119|
|Address:||A08 - Heydon-Laurence Building, The University of Sydney, NSW 2006 Australia|
|Links:||Marine Symbiosis Lab|
We study the biochemistry of cell-cell signals that maintain a stable symbiosis between intracellular algae (zooxanthellae) and their marine invertebrate hosts. Coral bleaching is one event that is evidence of disruption to coral symbioses.
We have isolated two signalling molecules from homogenized tissue of the scleractinian coral, Plesiastrea versipora that contains Symbiodinium algae.
One molecule, host release factor (HRF), stimulates the release of photosynthate from isolated algae and also reduces synthesis of algal starch and triglycerides suggesting that it acts to divert carbon from further algal metabolism to the host. It is a small molecule (Mr of 500-1,000) which has a high absorbance at 215 nm suggesting that it is probably a peptide. It also stimulates photosynthate release from the algae of several other symbioses including zoanthids, anemones and two other corals, as well as cultured algae from a jellyfish.
The second signalling molecule, photosynthesis inhibiting factor (PIF), partially inhibits photosynthetic carbon fixation in several symbiotic algae but not those from anemone or jellyfish. It is also a small molecule (Mr of 500-1,000) with a high absorbance at 215 nm, suggesting that it too is probably a peptide. We believe that these molecules play important roles in controlling algal carbon metabolism thus enabling the coral host to receive photosynthate for its own nutrition, and also regulating the numbers of intracellular algae to maintain a steady state population.
We are also studying the effects of pollutants on sessile marine organisms and have developed assays for the early detection of pollution damage in P. versipora. This research will help to prevent irreversible damage to marine organisms in a variety of habitats and also help to devise better management strategies of coral reefs.
- Grant, A., Trompf, K., Seung, D., Nivison-Smith, L., Bowcock, H., Kresse, H., Holmes, S., Radford, J., Morrow, P. (2010) Sub-cellular damage by copper in the cnidarian Zoanthus robustus Comp. Biochem. Physiol. Part C Toxicology. 152:256-262.
- Grant.A.J., Rémond, M., Starke-Peterkovic, T & R. Hinde. (2006) A cell signal from the coral Plesiastrea versipora reduces starch synthesis in its symbiotic alga, Symbiodinium sp. Comp. Biochem. Physiol. (Part A) 144, 458-463.
- Grant.A.J., Trautman, D.A., Menz, I. & Hinde, R. (2006) Separation of two cell signalling molecules from a symbiotic sponge that modify algal carbon metabolism. Biochem. Biophys. Res. Commun. 348, 92-98.
- Grant, A.J., T. Starke-Peterkovic, T., Withers, K.J.T., & Hinde, R. (2004) Aposymbiotic Plesiastrea versipora continues to produce cell signalling molecules that regulate the carbon metabolism of symbiotic algae. Comp. Biochem. Physiol.(Part A), 138: 253-259.
- Pile, A.J., Grant, A.J., Hinde, R.T. and M. A. Borowitzka (2003) Heterotrophy on ultraplankton communities is an important source of nitrogen for a sponge-rhodophyte symbiosis. J. Exp. Biol. 206: 4533-4538
- Grant, A.J., Graham, K., Frankland, S. & Hinde, R. (2003) Effect of copper on algal-host interactions in the coral Plesiastrea versipora. Plant Physiol. Biochem. 41: 383-390
- Grant, A.J., Trautman, D., Frankland, S & Hinde, R. (2003) A symbiosome membrane is not required for the actions of two host signalling compounds regulating photosynthesis in symbiotic algae isolated from cnidarians. Comp. Biochem. Physiol. (Part A) 135, 337-345
- Trautman, D.T., Hinde, R., Cole, L., Grant, A.J. & Quinnell, R. (2002) Visualisation of the symbiosome membrane surrounding Cnidarian algal cells. Symbiosis, 32(2):133-145, 2002.
- Grant, A.J., Rémond, M., Withers & Hinde, R. (2001) Inhibition of algal photosynthesis by a symbiotic coral. Hydrobiologia 461:63 -69.
- Bayne, B.L., Grant, A.J. & Trautman, D.A. (1999) Effects of added nutrients on the increase in biomass of benthic macroalgae in the Tuggerah lakes. Centre for Research on Ecological Impacts of Coastal Cities, Marine Ecology laboratories, University of Sydney.
- Grant, A.J., Rémond, M. & Hinde, R. (1998) A low molecular weight fraction from the symbiotic coral Plesiastrea versipora modifies the metabolism of symbiotic algae. Marine Biology, 130: 553-557.
- Withers, K.J.T., Grant, A.J. & Hinde, R. (1998) Effects of free amino acids on the isolated symbiotic algae of the coral Plesiastrea versipora (Lamarck): absence of a host release factor response. Comparative Biochemistry & Physiology, 120A: 599-607.
- Grant, A.J., Rémond, M., People, J., & Hinde, R. (1997) Effects of host-tissue homogenate of the scleractinian coral Plesiastrea versipora on glycerol metabolism in isolated symbiotic dinoflagellates. Marine Biology, 128: 665-670.
- Grant, A.J., Jessup, W. and Dean, R.T. (1993) Enzymatic degradation of radical damaged mitochondrial membrane components. Free Radical Research Communications, 19: 125-134.
- Grant, A.J., Jessup, W. and Dean, R.T. (1993) Inefficient degradation of oxidized regions of protein molecules. Free Radical Research Communications, 18: 259-267.
- Mackinnon, W.B., Dyne, M., Hancock, R., Leary, Grant, A.J., Russell, P. & Mountford, C.E. (1993) Malignancy-related characteristics of wild type and drug-resistant chinese hamster ovary cells. Pathology, 25, 268-276.
- Dean, R.T., Gebicki, J., Gieseg, S., Grant, A.J. & Simpson, J.A. (1992) Hypothesis: A damaging role in aging for reactive protein oxidation products? Mutation Research 275, 387-393.
- Grant, A.J., Jessup, W. & Dean, R.T. (1992) Accelerated endocytosis and incomplete catabolism of radical-damaged protein. Biochim. Biophys. Acta 1134, 203-209.
- Dean, R.T., Hunt, J.V., Grant, A.J., Yamomoto, Y. & Niki, E. (1991) Free radical damage to proteins: the influence of the relative localization of radical generation, antioxidants, and target proteins. Free Rad. Biol. Med. 11, 161-168.
- Grant, A.J., Russell, P.J. & Raghavan, D. (1990) Active and pro-plasminogen activator on the surface of human bladder cancer cells derived from a high grade invasive tumour. Biochem. Biophys. Res. Comm. 172, 870-876.
- Grant, A.J., Lerro, K. & C-Wu, K. (1990) Cell-associated elastase activities of rat mammary tumour cells. Biochem. Int. 22:1077-1084.
- Grant, A.J. (1990) Modifications to the lysine sepharose method of plasminogen purification which ensures plasmin-free glu-plasminogen. Biochem. Int. 20:519-527.
- Grant, A.J., Russell, P.J. & Raghavan, D. (1989) Elastase activities of human bladder cancer cell lines derived from high grade invasive tumours. Biochem. Biophys. Res. Comm.162:308-315.
- Badenoch-Jones, P., Ramshaw. I.A. & Grant, A.J. (1986) Cellular and secreted tumour plasminogen activator:the effects of NaCl. Experientia 42:433-435.
- Ramshaw, I.A., Badenoch-Jones, P., Grant, A.J., Maxted, M. & Claudianos, C. (1986) Enhanced plasminogen activator production by highly metastatic variant cell lines of a rat mammary adenocarcinoma. Invasion & Metastasis 6:133-144.
- Grant, A.J., Ramshaw, I.A., Badenoch-Jones, P., Eichner, R.D., & Hunt, N.R. (1986) Purification and characterization of a plasminogen activator inhibitor released by rat mammary adenocarcinoma cells. Eur. J. Biochem. 154:635-641.
- Grant, A.J. (1986) Products of rat mammary adenocarcinoma cells and their relevance to cancer metastasis. Ph.D.Thesis, John Curtin School of Medical Research, Australian National University, Canberra.
- Badenoch-Jones, P., Ramshaw, I.A. & Grant, A. (1985) An inhibitor of plasminogen activator produced by tumour cell fusion hybrids. Aust. J. Exp. Biol. Med. Sci. 63:343-352.