Cassel Dan , Professor

Phone:  (972)-4-8293408
Fax:  (972)-4-8295849

Building/Auditory:  Biology 319/2

Research Interests

Trafficking of proteins in the secretory system


Our laboratory is studying mechanisms of vesicular trafficking of proteins.  Focusing on the COPI system which mediates retrograde Golgi to ER transport, our studies are aimed at understanding the role of GTP binding and hydrolysis in vesicle budding and consumption, determining the mode of interaction between the components of the system, and defining the relative contribution of sub-compartment (ERGIC/Golgi/TGN) to the sorting of membrane and soluble cargo for retrograde transport.


In our studies we employ an array of molecular and cellular biology approaches including the expression of proteins in cultured mammalian cells, immunofluorescence microscopy, RNAi technology and yeast two-hybrid assays. We employ marker cargo protein to follow transport through specific trafficking routes. Our research also relies on biochemical and biophysical methods including protein purification and reconstitution in liposome-based systems, in vitro assays for measuring protein-protein interactions, and light scattering / fluorescence assays for measuring protein interaction with liposomes. 


Current projects (as of April 2014):


(i)     Development of a reversible  signal masking system for the control of protein trafficking. This system relies on the interaction of streptavidin with a peptide that is introduced near the traffic signal, and the reversal of the interaction by biotin. It was already successfully employed for regulated endocytosis, Golgi to ER traffic and import into the nucleus and peroxisomes

(ii)    Studies of the cellular compartmentalization of COPI-mediated transport relying on the synchronization of transport by the approach described above
 (iii)  Regulation of Arf-directed GTPase activating proteins by tyrosine kinases and by calcium-binding proteins
Positions are available for master and PhD students