Abstract
The Golgi complex is the primary sorting organelle at the nexus of the secretory and endocytic trafficking pathways. For example, virtually all proteins that eukaryotic cells display on their surface at the plasma membrane are first synthesized at the endoplasmic reticulum and then trafficked to the Golgi complex. Once at the Golgi, proteins find themselves at a crossroads: they may be trafficked to the plasma membrane, to endocytic organelles, to lysosomal organelles, back to the endoplasmic reticulum, or they may remain within the Golgi complex.
The regulators for all incoming and outgoing Golgi traffic are GTPases of the Rab and Arf families. Arfs and Rabs are activated by GEFs, which are master regulators of trafficking pathways. These proteins are responsible for making decisions about when to turn on different incoming and outgoing pathways. Despite knowing the identity of many the regulators, the molecular and atomic basis for their regulation remains poorly defined. The speaker used biochemical, structural, and cell biological methods to determine how these regulatory proteins make molecular decisions, and how those molecular decisions trigger membrane trafficking pathways. The speaker found that Golgi trafficking is regulated through GEF autoinhibition, positive feedback, and by a network of interactions between different incoming and outgoing GTPase trafficking pathways.
About the speaker
Prof Chris Fromme received his BA in Biology from Cornell University in 1999 and his PhD in Biochemistry from Harvard University in 2004. He then did postdoctoral work as a Miller Institute Fellow at University of California at Berkeley, where he began his work on how coat protein complexes control protein trafficking and membrane transport. He returned to Cornell University in 2008 and is currently the Associate Professor in the Weill Institute for Cell and Molecular Biology and the Department of Molecular Biology and Genetics.
Prof Fromme's research interests focus on how proteins and membranes are trafficked within eukaryotic cells and also the structure and function of the "exomer" vesicle coat.
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