LUJAN Hugo Daniel
congresos y reuniones científicas
Protein trafficking in Giardia lamblia
NATALIA GOTTIG; MARIA CAROLINA TOUZ; HUGO DANIEL LUJÁN
Tallin - Estonia
Congreso; Meeting of International Research Scholars - Howard Hughes Medical Institute; 2004
Howard Hughes Medical Institute
Giardia is a protozoan parasite of humans and a common cause of diarrheal disease worldwide.Besides its medical importance, Giardia is an excelent model for the study of the evolution of several cellular processes, given that it belongs to the earliest branches of the eukaryotic line of descent.Tosurvive outside the host"s intestine, Giardia undergoes adaptation by differentianting into an infective cyst;cysts are released with the feces and are responsible for the transmission of the disease among susceptible hosts.The encystation process includes the synthesis of the cyst wall components and the biogenesis of secretory organelles not present in non-encysting cell ,such as the Golgi apparatus and encystation-specific secretoty vesicles, wich are required for the transport of cyst wall constituents to the cell surface for later release and assembly uin the cyst wallAmong the components of the wall are two closely raleted leucine-rich proteins, wich we previously identified and characterized.Using biochemical, immunological, and molecular biological aproaches, we recently found that the alkaline C-terminal extension of CWP2 is involved in ESV formation, and we indentified two proteolytic enzymes necessary for both sensing the stimulus for encystation and processing the basic tail of CWP2 before incorporation into the cyst wall .Moreover, a granule -specific calcium-binding protein (GSP)was isolated and characterized.GSP expression knockdown demostrated that this protein is essential for exocytosis ok ESVs during cyst wall formation.We also developeda series of monoclonal antibodies against differnt regions of Giardia CWPs.Currently, these antibodies are being oused to study how cysat wall components are assembled ainto the extracellular structure that protects the parasite outside the intestinal of its host.