Figure 3.

Movement of Atg9 is Arp2-dependent. Wild-type and arp2-1 cells were grown to mid-log phase and shifted to nonpermissive temperature for 30 min before visualization. Movement of Atg9-3xGFP patches was tracked by time-lapse fluorescence imaging as described in Materials and Methods. The presented images are still frames of the indicated boxed regions shown at 2× enlargement and taken with a time lapse of 2 s for 60-s duration. (A) In wild-type cells, the Atg9-3xGFP puncta rapidly changed their location accompanied by fusion or division. (B) In the arp2-1 conditional mutant, there was no displacement of the majority of Atg9-3xGFP puncta during 60 s. Bar, 2 μm. (C) The single Atg9-3xGFP puncta indicated in A and B were tracked in the wild-type Atg9-3xGFP puncta indicated in A and B were tracked in the wild-type versus arp2-1 strains. Spatial positions of the centers of puncta were determined in each frame (with 2-s intervals) of a movie using ImageJ software, and consecutive positions were connected by lines. Open, larger circles denote the first position of each punctum. Bar, 500 nm.