The 2006 Roche Medal: Michael Ryan

Michael RyanMike Ryan is an Associate Professor in the Department of Biochemistry, La Trobe University. Mike undertook his PhD studies on molecular chaperones under the supervision of Professors Peter Hoj and Nick Hoogenraad, working at both La Trobe and later at the University of Adelaide. In 1997, Mike received an Alexander von Humboldt Research Fellowship and led a research group in the laboratory of Nikolaus Pfanner in Freiburg, Germany. His research focussed on the import of proteins into mitochondria in yeast. With colleagues in the Pfanner lab, he characterised translocase components of the outer mitochondrial membrane including the organiser Tom22 and the channel Tom40. By coupling an in vitro import assay with blue native PAGE, Mike and colleagues analysed the pathway of subunit assembly into membrane protein complexes. In particular this led to new insights into the biogenesis of the outer membrane TOM complex as well as the initial identification of a new sorting and assembly machinery (SAM). With Nils Wiedemann, he also addressed how precursors of the highly hydrophobic metabolite membrane carrier family can translocate across the outer membrane to reach their final destination, the inner membrane.

In 2000, Mike returned to the Department of Biochemistry at La Trobe as an ARC Fellow to study mitochondrial biogenesis in mammalian cells and became a faculty member in 2001. Following success in analysing assembly of TOM complex subunits, he turned to the challenge of understanding the assembly of the respiratory complexes and their defects that cause mitochondrial disease. Work on protein import has also continued and includes a collaboration with Jacqui Gulbis (WEHI) whose group solved the crystal structure of the small TIM complex that chaperones carrier precursors across the intermembrane space. In addition to this, members of his group also study the protein machinery involved in fission, fusion and distribution of mitochondria. Mike is also an investigator in the ARC Centre of Excellence for Coherent X-ray Science. In receipt of the award, Mike acknowledges former and current laboratory colleagues as well as his collaborators Nick Hoogenraad, Klaus Pfanner, David Thorburn and Jacqui Gulbis, and funding from the ARC and NHMRC.