A Nobel Prize For a New Perspective

Rahul Lodhavia |SQ Features writer | Online Journal Week 2

Any student who has studied biology has started off studying cells. Cells are the basic units of life and until twenty to thirty years ago, much was still not known about the intricacies of cells. Even today, not everything is known about all the functions of the many types of cells. However, one important function, the function of cell transport, was explored in great detail by three scientists and their work has become an integral part of the way we and future students learn about biology. Cell transport is absolutely key to maintaining cell life and consequently our lives as well. Without it, cells would not survive, leading to a host of neurological and immunological disorders. For their unearthing and understanding the facets of cell transport, James E. Rothman, Randy W. Schekman and Thomas C. Südhof were jointly awarded the 2013 Nobel Prize in Physiology or Medicine.

The system of cell transport functions like cargo ships. A specific procedure must be followed in order for the correct cargo to reach its designated destination. Cells have different “cargo compartments” called organelles that also require a system of organization. Additionally, these organelles have smaller motile cargo carriers called vesicles. Cells produce all types of molecules from hormones to neurotransmitters which makes their organization in cell transport extremely critical for proper function. Dr. Randy Schekman, fascinated by how a cell organizes its transport system in a precise fashion, studied the genetic basis of cell transport by using yeast as a model. He found that in yeast with defective transport mechanisms, vesicles carrying important molecules would pile up in a fashion similar to congested traffic. He discovered that this congestion was caused by mutations in three classes of genes. Dr. Schekman identified that these genes are responsible for the control and regulation of the intricate cell transport system. These discoveries provided a new perspective into the way cells operate which we still study today.

Once these vesicles know where to go, their molecules are accepted by receiving cells. Dr. James Rothman discovered that a protein cluster is responsible for allowing vesicles to dock and fuse with the receiving cell’s membranes. Like pieces of a puzzle, proteins on the vesicle connect perfectly with proteins on the receiving cell. Proteins on vesicles only have one type of complementary protein on the receiving cell, ensuring these pieces of the cellular puzzle fit perfectly, allowing for the correct cargo to reach its correct destination.  Coincidentally, these protein functions that Rothman discovered are controlled by the same genes Schekman unearthed.

Alongside the regulation and conformational specificity of the cell transport system, timing plays a huge role. Thomas Südhof studied this aspect of timing in nerve cells and their vesicles. He focused on studying the proteins sticking out of the vesicles containing neurotransmitters. Südhof wanted to know how the interactions among these proteins contributed to membrane fusion. He found that these proteins bring vesicles into docked positions and, because of an influx of calcium ions, force vesicles to fuse with their target membrane allowing for a release of neurotransmitter. Südhof’s work brought light to the very important process of synaptic transmission, and his work was later applied to hormone secretion, fertilization of an egg, and even immune response to foreign invaders.

These three scientists have uncovered a cellular process that is an integral process to our learning of the basic building block of life. Even more so, their work gives insight into how many neurological and immunological disorders work, including diabetes. This cellular process is absolutely key to life because without it cells would not be able to function. Their work has set the groundwork for the many studies of diseases around the world and has provided students with the basic understanding of an important cellular process that has served as a foundation for further learning and discovery.

Last year, we sat down for an interview with UC San Diego’s most recent Nobel Prize winner, Dr. Bruce Beutler ’76. He spoke about how the university prepared him for a career in medicine and research, and shared advice for undergraduates studying biology.