Further evaluation of the localization and functionality of hemagglutinin epitope- and fluorescent protein-tagged AtMinD1 in Arabidopsis thaliana.

Symmetric chloroplast division requires a prokaryote-derived division regulator protein MinD, whose subchloroplastic localization remains to be completely established. We investigated the localization and functionality of AtMinD1 (Arabidopsis thaliana MinD) fused with a dual hemagglutinin epitope (dHA) or a yellow fluorescent protein (YFP). AtMinD1-dHA, which successfully complemented the arc11/atminD1 mutant phenotype, was predominantly located at the envelope membrane and the mid-chloroplast constriction site. Meanwhile, AtMinD1-YFP was non-functional and showed suborganellar localization partly similar to that of AtMinD1-dHA. This prompts us to reevaluate earlier transgenic and transient expression studies using fluorescent protein-tagged AtMinD1.