Figure 4.

Dynamic localization of PleD to the stalked pole requires its activation by phosphorylation and is dependent on the polar kinases DivJ and PleC. (A) A nonphosphorylatable PleD mutant is impaired in polar localization. Phase contrast (PC) and corresponding fluorescent image of wild-type strain CB15N producing PleD_D53N-GFP from a low-copy number plasmid. Bar: left panel, 2 μm. (B) DivJ and PleC are required for the polar positioning of wild-type PleD-GFP. Phase contrast (PC) and corresponding fluorescent images of wild-type and divJ pleC mutant strain producing PleD-GFP from a low-copy number plasmid. (C) DivJ and PleC are not required for localization of the constitutive mutant PleD^*_D53N-GFP. Phase contrast (PC) and corresponding fluorescent images of wild-type and divJ pleC mutant strain producing PleD^*_D53N-GFP from a low-copy number plasmid. (D) An active GGDEF output domain is not required for localization of PleD. Phase contrast (PC) and corresponding fluorescent image of a pleD mutant strain producing PleD_GG368DE-GFP from a low-copy number plasmid. Filled arrows point to stalked poles in the phase contrast images (black) and to polar PleD-GFP foci in the fluorescent images (white). Open arrows point to nonpolar PleD-GFP foci.