Guest Speakers

The Ortega lab will be hosting a visitor who will be giving a talk on Wednesday Dec 21st at 11:00 am in MDCL 3023.

Tittle and abstract for the talk:

Aleksandar Necakov, Ph.D.
Developmental Biology/Structural and Computational Biology
The European Molecular Biology Laboratory (EMBL)

Bridging the Gap Between Light and Electron Microscopy: A novel correlative approach for elucidating the dynamics and subcellular distribution of early endocytic intermediates during embryonic development

Abstract
An extensive body of experimental evidence has given rise to the idea that endocytosis, the process by which cells internalize components of the extracellular milieu, has evolved from a set of simple routes dedicated to nutrient uptake into a complex molecular network that plays a central role in intercellular signaling. In fact, the prominent role of endocytosis in cell signaling is underscored by the disproportionate representation of mutations in the endocytic pathway in almost all human cancers, making it an important target for therapeutic intervention. In order to better understand the function and spatio-temporal organization of the early endocytic machinery I have used the early Drosophila embryo as a model system. In addition to the fact that the Drosophila embryo is genetically accessible, and that the core components of the endocytic machinery are highly conserved between flies and humans. it has proven invaluable as a model in elucidating the molecular basis of the endocytic control of apico-basal polarity, membrane trafficking, and the regulation of Metazoan cell-signaling. By employing live imaging in conjunction with a novel correlative light-electron microscopy approach I have been able to elucidate both the temporal dynamics and spatial distribution of molecular components of the early endocytic pathway at high resolution. This approach has allowed me to visualize the dynamic distribution of fluorescently tagged Rab5, a small, highly conserved, GTPase that plays an essential role in the early endocytic pathway, and to identify its association with subcellular structures in electron tomograms.Taken as a whole, this approach has the potential to integrate the power of Drosophila genetics and the availability of a wide range of fluorescently-tagged proteins in identifying the dynamics and subcellular distribution of any given protein of interest in order to better understand its function in a multicellular context.

Joaquin Ortega. Ph.D.
Associate Professor, Director
Co-Director, EM Facility
Department of Biochemistry and Biomedical Sciences
Michael G. DeGroote Institute for Infectious Disease Research
McMaster University, HSC 4H24
Hamilton. ON Canada L8S 4K1
905-525 9140 x22703.
http://web.me.com/ortegaj_mcmaster/Ortega_lab_web_site/Welcome.html