Speaker Biography

Gero Steinberg

Professor Steinberg studied Biology in Kiel, Germany, where he mainly focused on the ecology of marine and freshwater systems. After graduation he started a PhD in the laboratory of Prof. Manfred Schliwa in Munich, working on organelle transport and molecular motors in Neurospora crassa and later in the zygomycete Syncephalastrum racemosum. After a post-doctorate post in the lab of Prof. Richard McIntosh, working on Schizosaccaromyces pombe and Ustilago maydis, he joined the group of Prof. Regine Kahmann in Munich. There he established a research group addressing membrane trafficking, cell polarity and pathogenicity in the basidiomycete corn pathogen Ustilago maydis. In 2001 he followed Professor Kahmann to the Max-Planck Institute for Terrestrial Microbiology in Marburg, Gemany, taking a permanent C3 position, still working on different aspects of cellular dynamics in U. maydis. In 2007 Professor Steinberg moved to Exeter, UK, as Chair in Cell Biology and Director of the Bioimaging Centre. Many of his current scientific investigations have medical implications and consequently he became Honorary Professor at the Penninsula Medical School in Exeter. His work still addresses the cytoskeleton and membrane dynamics in fungal model systems, which, in some projects, is done with particular emphasis on the pathogenic potential of the smut fungus.

Abstract: Organelle transport: Stochastic or controlled?

In fungi intracellular transport of organelles and vesicles support numerous essential cellular processes, including secretion and endocytosis during tip growth. The underlying machinery consists of molecular motors that bind to their cargo and hydrolyse ATP to walk along the filamentous tracks of the cytoskeleton. In the current view, these transport processes are vectorial and are controlled by regulators, such as kinases and phosphatases. One example is the formation and uni-directional transport of secretory vesicles, which are thought to pinch off the trans-Golgi network. From there they are thought to travel to the growth region to fuse with the plasma membrane, where they exocytose their content. While this is an attractive concept, recent results challenge this simple concept.

Instead, it emerges that stochastic and non-controlled processes, such as random motor behaviour are much more prominent than previously anticipated. In this talk I will focus on endosome and secretory vesicle motility to illustrate how stochastic behaviour and cellular control cooperate to mediate membrane trafficking in filamentous fungi.