Signal Transduction through the Met Receptor Studied at the Single-Molecule Level

Abstract

The human receptor tyrosine kinase Met and its ligand hepatocyte growth factor (HGF) are essential during embryonic development and play an important role during cancer metastasis and tissue regeneration [1]. In addition, it was found that Met is also relevant for infectious diseases and is the target of different bacteria, amongst them Listeria monocytogenes that induces bacterial uptake through the surface protein internalin B (InlB) and causes human listeriosis [2]. Many of the mechanistic steps of Met activation, however, are still unclear.Here, we use single-molecule fluorescence microscopy techniques [3, 4] to unravel association and activation of Met receptor through its ligands, HGF and InlB. In particular, we use techniques which provide high temporal and spatial resolution and excellent statistics to study both the spatial distribution as well as the dynamics of Met receptor in eukaryotic cells. In addition, we investigate interactions with membrane microdomains.[1] Birchmeier C.; Birchmeier W.; Gherardi E.; Vande Woude G.F. (2003) Met, metastasis, motility and more. Molecular Cell Biology, 4, 915-925.[2] Shen Y.; Naujokas M.; Park M.; Ireton K. (2000) InlB-Dependent Internalization of Listeria is mediated by the Met Receptor Tyrosine Kinase. Cell, 103, 501-510.[3] Hohlbein, J.; Gryte, K.; Heilemann, M. & Kapanidis, A. N. (2010) Surfing on a new wave of single-molecule fluorescence methods. Physics and Biology, 7, 031001.[4] Heilemann, M.; van de Linde, S.; Mukherjee, A. & Sauer, M. (2009) Super-resolution imaging with small organic fluorophores. Angewandte Chemie, 48, 6903-6908.