Three win Nobel Prize for medicine

James E Rothman, Randy W Schekman, Thomas C. Südhof to be awarded for discovering transport mechanism of cells

 
By Kundan Pandey
Published: Monday 07 October 2013

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Two scientists from the US and one from Germany were announced winners of the Nobel prize for medicine, 2013, on Monday for discovering a fundamental process in cell physiology.

The prize committee explained that the three researchers have deciphered the mechanism by which molecules, such as hormones, neurotransmitters, cytokines and enzymes produced in the cell, move within it and are then exported to other cells and delivered at the exact location and at exact time.

For instance, insulin is manufactured and released into the blood and chemical signals called neurotransmitters are sent from one nerve cell to another.  Understanding this precise mechanism is an important development in medicine. Disturbances in this system have deleterious effects and contribute to conditions such as neurological diseases, diabetes, and immunological disorders, the official press release of the Nobel Prize said.

The award has been given to Randy W Schekman associated with University of California, Berkeley, CA, USA, James E Rothman, associated with Yale University, New Haven, CT, USA and Thomas C Südhof, associated wiith Stanford University, Stanford, CA, USA.

In the 1970's, Randy Schekman studied the transport system in yeast cells which had defective transport machinery. He found that the vesicles in which the molecules were packaged failed to be transported and accumulated within the cell. He identified that three classes of genes were responsible for this defect and controlled different aspects of the transport.

Similarly, James Rothman found that how the cargo is transported to the exact location where it is needed. While studying vesicle transport in mammalian cells in the 1980s and 1990s, he found that protein complex facilitate vesicles to mingle with the target membranes. Subsequently, the protein on vesicle and membrane stick together. Because this binding happens specifically with the target membrane, it ensures that the cargo is delivered to exact location. The same principle works in cells also, a binding between vesicles with the outer membrane of cells takes place and contents are released.

Later, Thomas Südhof discovered how the nerve cells communicate with one another in the brain. Sudhof found that these vesicles only release their content when they get signals from their neighbours. He found calcium sensitive proteins in the nerve cells which facilitated these signals. He identified molecular machinery that responds to an influx of calcium ions and directs neighbour proteins rapidly to bind vesicles to the outer membrane of the nerve cell.

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