Figure 4.

Western blot analysis and immunofluorescence of GFP-SpoIIQ and SpoIIQ-myc. (A) Immunoblot of GFP-SpoIIQ depicting specific proteolytic cleavage during engulfment. Full-length GFP-SpoIIQ is marked with an asterisk (^*). (B) Western blot of SpoIIQ-myc shows no smaller degradation product. Full-length SpoIIQ-myc is marked with an asterisk (^*). Immunofluorescence samples were taken at (C, E) t₂ and (D, F) t₃ and stained with Mitotracker Red (membranes in red), DAPI (DNA in blue) and SpoIIQ (GFP or Myc in green). (C, D) Localization patterns for GFP-SpoIIQ observed for fixed cells are the same as with live cells. (E, F) Localization of SpoIIQ-myc suggests that degradation occurs at the C-terminus of the protein since early patterns are similar to GFP-SpoIIQ, but little signal is observed in late sporangia. Scale bar, 2 μm.