Question

What is the effect of expressing a dominant active form of the small GTPase Rac1 in a human neutrophil

Answer 1

Answer:

The neutrophil forms multiple lamellipodia extensions

Explanation:

Neutrophils are white blood cells (granulocytes) which comprise the first line of defense in the innate immune system. The lamellipodium (in plural, lamellipodia) is a cytoskeletal actin extension found in mobile cells, whose main functions are cell motility and migration.  Rac1 is a member of the Rho GTPase protein family which is involved in actin-myosin cytoskeletal reorganization of neutrophil cells in response to microorganism infections. In this regard, it has been shown that Rac1 controls the initial uncapping of actin ends in order to regulate cytoskeleton dynamics, thus regulating lamellipodia formation. By using mice as models, researchers observed that Rac1 constitutive activation may lead to the formation of multiple lamellipodia in neutrophils.