Researchers Capture Images that Illuminate One of Cell's Mysteries

Jul 18, 2008 By Bill Hathaway

(PhysOrg.com) -- Within human cells, tiny membrane-bound compartments called vesicles shepherd biomolecules from place to place.

How these vesicles form, move and finally fuse to deliver cargo at a particular destination largely remains a mystery, now being investigated by Yale researchers Karin Reinisch and Susan Ferro-Novick.

The scientists, both of the Department of Cell Biology, have focused on understanding the molecular basis for the final steps of cargo delivery, a process believed to be important in specifying the correct delivery address for a particular vesicle.

In the June issue of the journal Cell, they describe how they used X-ray crystallography to visualize a key step in this process.

A decade ago, Ferro-Novick’s lab first discovered the large multi-protein complex known as TRAPPI that plays a role in tethering a vesicle to its target. In a technically demanding feat, the team captured an image of TRAPPI as it activates a regulatory protein within the cell. Activation of the protein, known as Rab GTPase Ypt1, is a crucial step leading to the fusion of the vesicle. The study provides a framework for understanding how the many proteins involved in vesicle docking cooperate.

Large protein assemblies are difficult to crystallize and to visualize at an adequate level of detail, but the team led by Yiying Cai, lead author of the study, was able to overcome those technical hurdles.

“We were able to get these results only because Yiying was relentless in preparing samples of sufficient quality,” Reinisch says.

Other team members currently in the Department of Cell Biology include Darina Lazarova, Shekar Menon and Anthony Sclafani. Key contributions were also made by Harvey Chin in the lab of Enrique De La Cruz in the Department of Molecular Biology and Biophysics.

Provided by Yale University

Explore further: 'Office life' of bacteria may be their weak spot

add to favorites email to friend print save as pdf

Related Stories

Researchers discover new producer of crucial vitamin

20 hours ago

(Phys.org) —New research has determined that a single group of micro-organisms may be responsible for much of the world's vitamin B12 production in the oceans, with implications for the global carbon cycle and climate change.

Recommended for you

Transparent larvae hide opaque eyes behind reflections

5 hours ago

Becoming invisible is probably the ultimate form of camouflage: you don't just blend in, the background shows through you. And this strategy is not as uncommon as you might think. Kathryn Feller, from the University of Maryland ...

Peacock's train is not such a drag

6 hours ago

The magnificent plumage of the peacock may not be quite the sacrifice to love that it appears to be, University of Leeds researchers have discovered.

Iberian pig genome remains unchanged after five centuries

11 hours ago

A team of Spanish researchers have obtained the first partial genome sequence of an ancient pig. Extracted from a sixteenth century pig found at the site of the Montsoriu Castle in Girona, the data obtained indicates that ...

User comments : 0