A vesicle transport system inside chloroplasts

Intracellular transport via membrane vesicle traffic is a well known featur e of eukaryotie cells. Yet, no vesicle transport system has been described for prokaryotes or organelles of prokaryotic origin, such as chloroplasts a nd mitochondria. Here we show that chloroplasts possess a vesicle transport system with features similar to vesicle traffic in homotypic membrane fusi on. Vesicle formation and fusion is affected by specific inhibitors, e.g. n ucleotide analogues, protein phosphatase inhibitors and Ca2+ antagonists. T his vesicle transfer is an ongoing process in mature chloroplasts indicatin g that it represents an important new pathway in the formation and maintena nce of the thylakoid membranes. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.