Mechanisms and roles of transport proteins at the blood-brain barrier, in red blood cells and in malarial parasites
The ATP Binding Cassette superfamily of proteins contains several members that act as transporters, so providing protection to cells and tissues against cytotoxic stresses. Past work by our groups has examined the mechanisms by which these transporters bring about transport of various different substrates, identifying the particular proteins involved, looking at their specific locations at the blood-brain barrier and factors regulating their expression under normal and pathological conditions. Regulatory factors include the influences of pH, hypoxic and oxidative challenge and signalling from other brain cell types. In a separate series of studies the functions of these transporters in red blood cells and in malarial parasites in the erythrocyte stages of their life cycle have been investigated. Other transporters of interest have been those regulating the ionic content of both endothelial cells at the blood-brain barrier and of malaria parasites. Determining if any of these transporters make good targets for therapeutic intervention has been a major aim and, in the context of erythrocyte stage malarial parasites, this work continues in collaboration with the group of Prof. Kiaran Kirk at ANU, Canberra, Australia. The current hypothesis is that one of the ABC transporters is the glutathione conjugate transporter that must exist in the parasite membrane.
Techniques that were employed in the above work included: tissue isolation; primary cell culture; molecular biological methods for modifying gene expression and for manipulating and analysing RNA, DNA and proteins; immunocytochemistry; transport studies with radiolabelled and with fluorescent tracers; visualising and quantifying intracellular distribution of fluorescent substrates, analysing intracellular pH and measuring ion channel activity using intracellular recordings.
Enquiries about any of our work current or past are welcome.