Cell's Decision-Making Circuitry Scrutinized by UCSF Research Team

By Wallace Ravven, UCSF News Services | January 26, 2006

A UCSF research team has gained a new glimpse into the circuitry that directs the fate of cells: whether they will grow, change shape or succumb to pathogens.

Cells monitor their environment and make vital decisions by using complex circuits made up of molecules known as signal transduction proteins. One of the most common units used to build these circuits is a class of enzymes called protein kinases, capable of changing the action of other proteins. Different kinases often link together into large cascades or circuits that allow specific cell responses. Cancer, in which cells undergo uncontrolled growth, often progresses by short-circuiting normal kinase cascades.

A major puzzle in biology has been trying to understand how the many different kinds of kinases in a cell normally link together into precisely controlled circuits. Recent research has revealed that they are often physically organized into large assemblies by "scaffolding" proteins that appear to tether a specific set of kinases together. The tethering determines what circuits the different kinases form and the degree of action the circuit exerts on the cell.

A team led by Wendell Lim, PhD, UCSF professor of cellular and molecular pharmacology, reports this week how a scaffold protein interacts with a kinase and shows for the first time that scaffolds can directly affect the activity of a kinase, in addition to passively tethering it to its partners.

Read more at Wallace Ravven, UCSF News Services