Kinetic analysis of the translocation from the cytoplasm to the plasma membrane of GFP-tagged CRAC (Cytosolic Regulator of Adenylyl Cyclase-a PH domain containing protein) in response to a uniform increase in chemoattractant concentration. Frames were taken every 2 seconds. The chemoattractant was added just before the cell goes out of focus. From C.A. Parent and P.N. Devreotes,  Johns Hopkins Medical Institutions.

Confocal image of GFP-tagged CRAC in living amoebae undergoing chemotaxis. CRAC-GFP specifically translocates to the leading edge of newly elicited pseudopods. The chemoattractant gradient is established using a micropipet located near the upper right corner of the frame. Images were captured every 5 seconds. From C.A. Parent and P.N. Devreotes, Johns Hopkins Medical Institutions.

Translocation of CRAC-GFP in cells lacking actin filament formation. Cells chemotaxing towards the micropipet in the lower portion of the frame were treated with Latrunculin A and observed within the next few minutes. Images were captured every 5 seconds. From C.A. Parent and P.N. Devreotes, Johns Hopkins Medical Institutions.

Immobilized CRAC-GFP expressing cells can respond to changes in chemoattractant gradients. Latrunculin A treated cells were subjected to changing gradients of chemoattractants by moving the micropipet around the cell. Images were captured every 5 seconds. From C.A. Parent and P.N. Devreotes, Johns Hopkins Medical Institutions.