AXEL NOHTURFFT Molecular and Metabolic Signalling Centre Division of Basic Medical Sciences St. George's, University of London Cranmer Terrace London SW17 0RE +44 (0)20 8725 0902 (Office) +44 (0)20 8725 5809 (Lab)

Membrane biogenesis and transport:

Membrane biogenesis requires the assembly of many different proteins and lipids. In addition, membrane vesicles must often be transported to specific target sites in the cell. Both aspects of membrane biogenesis are being studied in this lab. Particular emphasis is placed on changes in membrane synthesis and transport that occur in response to phagocytosis.

In certain cell types particle envelopment can consume up to 30% of cellular membrane pools and a large fraction of these membranes is provided at the expense of endosomes. In response to this re-appropriation of organelles, cells synthesize new membranes within a few hours. During phagocytosis organelle biogenesis can thus be studied in relative isolation and we are asking how the synthesis of lipids and endosomal proteins is controlled and coordinated.

Following phagocytosis, the resulting vacuole or "phagosome" fuses with lysosomes. These vesicles contain digestive enzymes, toxic peptides and other molecules that are required for killing and digestion for example of phagocytosed bacteria. A second aspect of our research is concerned with the mechanisms by which lysosomes are targeted to phagosomes and the question of how these interactions are controlled under specific physiological circumstances.