Protein Transport Across the Thylakoid Membrane

Abstract

Protein transport across the thylakoid membrane of chloroplasts can take place by at least four independent pathways which are characterized as Sec-dependent, SRP-dependent, delta-pH/TAT-dependent or spontaneous. Each pathway operates with a distinct mechanism and transports specifically only a subset of thylakoid proteins. In addition to giving a brief overview about protein transport across the thylakloid membrane in general, this article focusses on a few interesting aspects of the delta-pH/TAT-dependent pathway which is capable of translocating folded polypeptides across the thylakoid membrane, as well as on the phylogeny of spontaneous protein insertion into the thylakoid membrane.