One of the most powerful ways of studying the function of a protein is
to specifically block its activity within cells. Over the past decade, dominant-inhibitory
proteins have emerged as popular tools with which to accomplish this task;
these mutated proteins interfere with the function of their normal cellular
counterparts or with proteins that interact with them. This approach has been
used extensively in the elucidation of signal-transduction cascades, such
as those involving Ras-family proteins. Here I discuss the power and potential
pitfalls of using dominant-inhibitory Ras proteins.
