Stromal cell-derived factor 1 (SDF1) is a secreted protein that plays a major role in guiding the migration of various cells during development. It binds to a G-protein-coupled receptor on the surface of the migrating cell, which in turn activates a trimeric G protein containing a Gᵢ subunit. Pertussis toxin (PTX) modifies and inactivates the Gᵢ subunit. What would you expect to observe if migrating cells are treated with PTX?
A) They migrate toward the source of SDF1.
B) They migrate away from the source of SDF1.
C) They migrate in a certain direction chosen randomly.
D) They move in small steps in random directions.
E) They lose their motility.

Question

Quizplus · Accepted Answer

SDF1 biases the site of membrane protrusions (blebs) toward its source, but the cells still display blebbing even when SDF1 signaling is perturbed.

Stromal Cell-Derived Factor 1 (SDF1) Is a Secreted Protein That