Endosymbiotic chloroplasts in molluscan cells contain proteins synthesized after plastid capture.

Endosymbiotic chloroplasts within the cells of the ascoglossan slug Elysia chlorotica synthesize a variety of proteins including the large subunit of ribulose-1,5-bisphosphate-carboxylase oxygenase (RuBisCO) and the photosystem II protein D1. In addition, the effects of protein synthesis inhibitors suggest that some chloroplast-associated proteins are synthesized in the animal cytosol and subsequently translocated into the chloroplasts. Thus, the plastids not only synthesize proteins during this long-lived association, but the host cell seems to play a role in plastid protein turnover.