Our studies of the SECE components of the chloroplast Sec translocases lead us to hypothesize that mechanisms for differential targeting of tail-anchored proteins to specific membranes must exist within chloroplasts. Tail-anchored proteins have a unique structure, with a single transmembrane domain close to the C-terminus. In the cytosol, these are post-translationally targeted by a specialized system that includes the targeting factor GET3. Plants contain multiple GET3 homologs and one of these is targeted to the chloroplast. We are investigating whether the chloroplast GET3 homolog and/or other proteins play a role in membrane-specific targeting of tail-anchored proteins within chloroplasts.