LA JOLLA, CA----You might think you have nothing in common with mustard except hotdogs. Yet based on research in a plant from the mustard family, Salk scientists have discovered a possible explanation for how organisms, including humans, directly regulate chemical reactions that quickly adjust the growth of organs. These findings overturn conventional views of how different body parts coordinate their growth, shedding light on the development of more productive plants and new therapies for metabolic diseases.
Metabolism refers to all the chemical reactions in the body that drive the basic processes of life: birth, growth, reproduction, digestion, sensing and so on. These reactions are orchestrated and quickened by molecular machines called enzymes. Until now, it was believed that each metabolic function required an entirely separate enzyme pathway. Further complicating the picture, scientists focused almost exclusively on genes switching on and off as the means by which each step in the pathway was regulated, roughly analogous to waiting for a part to be ordered then manufactured before the engine can run.
In a paper in this week's Nature Chemical Biology, Salk scientists and Howard Hughes Medical Institute Investigators Joanne Chory and Joseph P. Noel and their colleagues show that metabolic steps can be much more streamlined and linked. Unexpectedly, two separate pathways originally thought to be controlled solely by gene switches can have enzyme canals between them, allowing them to quickly share abundant building blocks for two separate chemical messages known as hormones. These hormones are manufactured in one part of the body in response to changes in environment and quickly alter growth in other parts. Many times, at least two hormones are needed to quickly adjust growth of different tissues in response to a single event.
"Genes are the instruction manuals for how cells build specific enzymes in a pathway, but if you hav
|Contact: Andy Hoang|