Cells reproduce by duplicating their genomes and other components and then distributing these components equally into two daughter cells. The carefully orchestrated series of events that leads to cell duplication and division is called the cell cycle. Cell-cycle events are timed and coordinated by a network of regulatory proteins called the cell-cycle control system.
The Morgan Lab's research goal is a detailed biochemical understanding of the proteins that make up the cell-cycle control system. Much of the research has focused on the cyclin-dependent protein kinases (Cdks). These highly conserved enzymes are activated at specific cell cycle stages and are directly responsible for triggering major cell cycle events such as DNA replication and mitosis. Members of the Morgan lab study the molecular mechanisms that govern progression through the cell division cycle using a variety of biochemical and genetic approaches, primarily in budding yeast, to study the cell biology and enzymology of two regulatory enzymes: the cyclin-dependent protein kinases and the ubiquitin ligase APC, particularly important in controlling mitosis.
The lab uses a variety of different model systems, including budding yeast and mammalian cells, to address fundamental questions in the control of cell division by Cdks and other regulatory molecules. Major projects in the lab include the following:
Targets of the Cdks: Little is known about the mechanisms by which Cdks trigger cell-cycle events. It is generally assumed that Cdks, like other protein kinases, exert their effects by phosphorylating target proteins, but few of these target proteins have been identified. The lab uses a novel 'chemical genetic' approach, conceived by our UCSF colleague Kevan Shokat, to search the yeast and vertebrate proteomes for Cdk substrates.
Exit from mitosis: Morgan Lab explores the regulatory mechanisms that complete the cell cycle in late mitosis. Much of this work focuses on a mysterious multi-subunit enzyme called the Anaphase-promoting complex (APC). The APC is a ubiquitin-protein ligase that catalyzes the attachment of the protein ubiquitin to substrate proteins, thereby targeting these substrates for destruction. In late mitosis, the APC triggers the proteolytic destruction of several cell-cycle regulators, including cyclins. The lab is interested in the biochemical reactions catalyzed by the APC and in the regulatory systems that control these reactions.
David Morgan earned his undergraduate degree in Animal Biology from the University of Calgary before pursuing a PhD in Endocrinology at University of California, San Francisco. He completed subsequent postdoctoral research at UCSF before joining the departments of Physiology and Biochemistry and Biophysics as a Professor.
Dr. Morgan is currently the Vice-Chair of the Department of Physiology as well as the Director of the UCSF Tetrad Graduate Program. He holds several awards including UCSF Medical School Teaching Award for Outstanding Lecture Series, UCSF Kaiser Award for Excellence in Teaching in the Classroom Setting. He holds the Jack D. and DeLoris Lange Endowed Chair in Physiology, and is a Royal Society of London Fellow.
Jonathan Asfaha, Graduate Student
Chris Carlson, Graduate Student
Nairi Hartooni, Graduate Student
Arda Mizrak, Graduate Student
Laura Rosen, Postdoctoral Fellow
Drew Thacker, Postdoctoral Fellow
Dora Scott, Executive Assistant