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Research

Broad Research Interests of the Department

 

Biochemistry

 

Prof Adrienne L. Edkins -Cancer and Stem Cell Biology

Our group is studying the biochemistry and cell biology of the molecular chaperone, Hsp90, in cancer and stem cell biology. We use a range of biochemical (recombinant protein expression), molecular (quantitative RT-PCR, RNA interference) and cell biological (transfection, confocal microscopy and flow cytometry) techniques in order to elucidate the activity of Hsp90 and its co-chaperone, Hop, in specific cellular processes that underpin cancer and stem cell biology. In addition to our research on human chaperones, our research group is interested in comparative studies of Hsp90 complex from other organisms. These studies are interesting in that they may identify differences between the different systems that could be useful in understanding the species specific features of chaperones and may identify exploitable differences between the structure of the human and Hsp90 from other species to complement our studies to identify novel natural product inhibitors of Hsp90.

 

Prof Heinrich Hoppe - Malaria Parasite Cell Biology

Our group is predominantly focused on exploring ADP-ribosylation factor (ARF) GTPases as drug targets for the development of novel therapeutics against malaria and cancer. This entails the development of plate-based assays to robustly detect the activation and deactivation of ARF GTPases by regulatory proteins, implementing these assays in screens for novel ARF inhibitors and performing biochemical and cell biological experiments to elucidate the effects of the inhibitors on cultured cells/parasites. A second activity of the group is to perform routine phenotypic assays to screen compounds for activity against malaria parasites (Plasmodium falciparum), trypanosomes (Trypanosoma brucei) and mammalian cells. These screens are conducted to facilitate the vibrant drug discovery programs in the Rhodes University Centre for Chemico- and Biomedicinal Research.

 

Prof Brett Pletschke - Enzyme Biotechnology, Bioproducts

Our group’s research interest lies in the field of enzyme biotechnology, more specifically in the use of enzymes in bioconversion to generate bioproducts from renewable biological resources, e.g. lignocellulose and seaweeds (macroalgae) for the bioeconomy. Since 2006 we have established ourselves firmly in the area of carbohydrate active enzymes (CAZymes) and the synergisms between these enzymes (cellulases, xylanases and mannanases) - mainly for optimising biofuel production.  Currently (2019), we are looking at xylanases for improving digestibility of animal feeds, mannanases for the production of prebiotic manno-oligosaccharides (MOS), and the extraction of seaweed derived fucoidans and other enzyme inhibitors compounds from seaweeds for use as anti-diabetic/anti-obesity/anti-cancer agents.

 

Prof Ozlem Tastan Bishop - Bioinformatics

Prof Tastan Bishop's research interest combines structural bioinformatics and comparative genomics. Research projects in her group range from drug discovery to agricultural studies to databases. Various bioinformatics approaches are used to model protein structures, to analyse protein structure - function relationship, to do protein-ligand and protein-protein docking as well as molecular dynamics calculations. Further, tool development and database construction are important aspects of the group's work. For further information, visit RUBi webpage (click here).

 

Dr Brendan Wilhelmi - 

Dr Wilhelmi's research group investigates cytochrome P450 metabolism as well as target enzymes of neurodegenerative diseases. These enzymes are cloned and expressed, purified and their activity optimised and investigated against compounds of interest. The molecular bar-coding research aims to identify specific markers in different species, including single nucleotide polymorphisms in P450, cytochrome c oxidase and other hypervariable DNA regions for both diagnostic and identification purposes.

 

Dr Jo-Anne de la Mare - Novel inhibitors for triple negative breast cancer

Dr de la Mare is a member of the Biomedical Biotechnology Research Unit. Her research focuses on tripple-negative breast cancer (TNBC), a highly aggressive subtype of the disease that lacks the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2/neu), making it very difficult to treat. Highly relevant to the African context is the fact that TNBC has been shown to be more prevalent in black women. This subtype has been linked to earlier age of onset, higher mortality and greater risk for metastasis. To date there remain limited treatment options available for TNBC patients. Dr de la Mare’s work focuses on the characterisation of TNBCs as well as the screening of novel small molecules of natural and synthetic origin against TNBC and other cancer cell lines. These novel compounds are sourced via an extensive network of local collaborators working in medicinal chemistry. An important part of the preclinical drug discovery process is the elucidation of the mechanism of action of a particular compound, the mode of cell death induced and signal transduction pathways perturbed. In particular, Dr de la Mare is interested in apoptosis and autophagy as cell death mechanisms and the role of DNA damage in mediating cytotoxicity. Dr de la Mare is currently engaged in a Sandisa Imbewu-funded collaboration with Prof Edkins, Prof Hoppe and Dr Abrahams that is focused on establishing a medium-high throughput mechanistic screening platform for both infectious and non-communicable diseases.

 

Microbiology

 

Prof Joanna Dames- Mycorrhizal Research Group

Mycorrhizal fungi are soil fungi which form a symbiotic relationship with the roots of the majority of plant species including many economically important crops. The Mycorrhizal Research Laboratory is dedicated to research in this field and research has focused on aspects of their biology, ecology, characterization, biodiversity, commercial application, their interaction with other soil microorganisms as well as benefits to both the soil environment and plant production.  Mycorrhizal types of interest are the ectomycorrhizal fungi, the arbuscular mycorrhizal fungi and the ericoid mycorrhizal fungi because of their importance in the Forestry, Agriculture, Horticulture and Rehabilitation industries.

 

Prof Rosemary Dorrington - Microbial Ecology and Marine Natural Products Research

This research forms part of a multidisciplinary programme (Chemistry, Marine Biology Geography and Microbiology) to study the role of the microbiota (focusing on bacteria and viruses) in marine ecosystems. Research projects include the role of the microbiota in determining ecosystem health in estuarine systems, the impact of global change on marine and terrestrial ecosystems in the Southern Ocean and studies on microbial symbionts associated with marine invertebrates and their  bioactive secondary metabolites.

 

Prof Caroline Knox - Molecular Virology

Research in Dr Knox’s laboratory is conducted in collaboration with Professor Martin Hill (Department of Zoology and Entomology, Rhodes University) and Dr Sean Moore (Citrus Research International) and focuses on the isolation and genetic characterisation of baculoviruses for the biocontrol of economically important insect pests. A second research interest, in collaboration with Professor Tom Wileman (University of East Anglia, UK) involves an investigation into the molecular mechanisms by which Picornaviruses interact with host cells during infection. Using biochemical assays and confocal microscopy, we are attempting to identify host components utilised by these viruses during the replication cycle.

 

Dr Ellen Ledwaba - 

One Health-related water quality and hygiene aspects, bacterial pathogenesis mechanisms, antimicrobial resistance and the transmission pathways of infectious pathogens.

 

Last Modified: Mon, 19 Feb 2024 09:13:03 SAST

Research

Cancer and Stem Cell Biology

Prof Adrienne L. Edkins

Our group is studying the biochemistry and cell biology of the molecular chaperone, Hsp90, in cancer and stem cell biology. We use a range of biochemical (recombinant protein expression), molecular (quantitative RT-PCR, RNA interference) and cell biological (transfection, confocal microscopy and flow cytometry) techniques in order to elucidate the activity of Hsp90 and its co-chaperone, Hop, in specific cellular processes that underpin cancer and stem cell biology. In addition to our research on human chaperones, our research group is interested in comparative studies of Hsp90 complex from other organisms. These studies are interesting in that they may identify differences between the different systems that could be useful in understanding the species specific features of chaperones and may identify exploitable differences between the structure of the human and Hsp90 from other species to complement our studies to identify novel natural product inhibitors of Hsp90.

Malaria Parasite Cell Biology

Prof Heinrich Hoppe

Our group is predominantly focused on exploring ADP-ribosylation factor (ARF) GTPases as drug targets for the development of novel therapeutics against malaria and cancer. This entails the development of plate-based assays to robustly detect the activation and deactivation of ARF GTPases by regulatory proteins, implementing these assays in screens for novel ARF inhibitors and performing biochemical and cell biological experiments to elucidate the effects of the inhibitors on cultured cells/parasites. A second activity of the group is to perform routine phenotypic assays to screen compounds for activity against malaria parasites (Plasmodium falciparum), trypanosomes (Trypanosoma brucei) and mammalian cells. These screens are conducted to facilitate the vibrant drug discovery programs in the Rhodes University Centre for Chemico- and Biomedicinal Research.

Enzyme Biotechnology, Bioproducts

Prof Brett Pletschke

Our group’s research interest lies in the field of enzyme biotechnology, more specifically in the use of enzymes in bioconversion to generate bioproducts from renewable biological resources, e.g. lignocellulose and seaweeds (macroalgae) for the bioeconomy. Since 2006 we have established ourselves firmly in the area of carbohydrate active enzymes (CAZymes) and the synergisms between these enzymes (cellulases, xylanases and mannanases) - mainly for optimising biofuel production.  Currently (2019), we are looking at xylanases for improving digestibility of animal feeds, mannanases for the production of prebiotic manno-oligosaccharides (MOS), and the extraction of seaweed derived fucoidans and other enzyme inhibitors compounds from seaweeds for use as anti-diabetic/anti-obesity/anti-cancer agents.

Bioinformatics

Prof Ozlem Tastan Bishop

Prof Tastan Bishop's research interest combines structural bioinformatics and comparative genomics. Research projects in her group range from drug discovery to agricultural studies to databases. Various bioinformatics approaches are used to model protein structures, to analyse protein structure - function relationship, to do protein-ligand and protein-protein docking as well as molecular dynamics calculations. Further, tool development and database construction are important aspects of the group's work. For further information, visit RUBi webpage (click here).

Exploring complex ecosystems

Dr Brendan Wilhelmi

Exploring complex ecosystems

Dr Wilhelmi's research group investigates complex microbiomes and their functions using a combination of meta-barcoding and metabolomics. The main focus of the research group is the research of the biology of soilless plant growth systems. In a country where food security and erratic water resources are of increasing concern, water based agricultural systems may provide a viable alternative to food production. These growth systems are dependent on a constant supply of nutrients to plants, which is influenced by the water chemistry, as well as the bacterial populations that mineralise organic matter in these ecosystems. In the case of aquaponics, the research focusses on identifying the bacterial populations and their possibly functions. The research includes the investigation of nutrient availability, its effect on fish and plant health, and nutritional biomarkers in the plants.

The Female Cancers Research at Rhodes University (FemCR2U)

Dr Jo-Anne de la Mare

The Female Cancers Research at Rhodes University (FemCR2U) group focuses on preclinical drug discovery for female cancers including triple negative breast cancer (TNBC) and cervical cancer. This work is made possible by a growing network of collaborators from across South Africa, including chemists from six provinces. The screening and characterization of novel inhibitors for TNBC is funded by the National Research Foundation. In addition, a recent award by the Medical Research Council of South Africa as part of the MRC-EC-SHIP programme will see the group attempting to establish cervical cancer cell lines from biopsy samples from Eastern Cape women, towards more relevant disease models for the African context, as well as allowing for genetic characterization of such lines towards the identification of novel driver mutations for this disease.

Mycorrhizal Research Group

Prof Joanna Dames

Mycorrhizal fungi are soil fungi which form a symbiotic relationship with the roots of the majority of plant species including many economically important crops. The Mycorrhizal Research Laboratory is dedicated to research in this field and research has focused on aspects of their biology, ecology, characterization, biodiversity, commercial application, their interaction with other soil microorganisms as well as benefits to both the soil environment and plant production.  Mycorrhizal types of interest are the ectomycorrhizal fungi, the arbuscular mycorrhizal fungi and the ericoid mycorrhizal fungi because of their importance in the Forestry, Agriculture, Horticulture and Rehabilitation industries.

Microbial Ecology and Marine Natural Products Research

Prof Rosemary Dorrington

More than half of new pharmaceutical drugs on the market or in clinical trials are natural products (NPs) and their derivatives, the majority of which come from marine sources. Prof Dorrington’s research is focused on harnessing the pharmaceutical potential of bioactive marine NPs produced by marine sponges, ascidians and their associated microbiota. The biodiscovery pipeline includes searching for new invertebrate species producing novel bioactive NPs, using metabolomics and microbial genomics approaches to investigate environmental factors that influence secondary metabolite production and to elucidate putative biosynthetic pathways

Molecular Virology

Prof Caroline Knox

Research in Prof Knox’s laboratory focuses on the molecular biology of two economically important families of viruses: the Baculoviridae and the Picornaviridae. Baculoviruses are double-stranded DNA viruses that infect insects and can therefore be exploited for the control of phytosanitory crop pests such as the false codling moth. This research, conducted in collaboration with the Centre for Biological Control (Rhodes University) and Citrus Research International (Port Elizabeth) involves the genetic and biological characterisation of viruses infecting a range of crop pests. Picornaviruses are single-stranded RNA viruses that cause a range of serious human and animal diseases. This research involves an investigation into the molecular mechanisms by which Picornaviruses interact with host cells during replication and assembly, with a view to uncovering novel antiviral strategies for disease control.