title: Evidence for SecA- and delta pH-independent insertion of D1 into thylakoids.
abstract: Many nuclear-encoded proteins are targeted into chloroplast thylakoids by an azide sensitive Sec-related mechanism or by a delta pH-driven mechanism. In this report, the requirements for the integration of chloroplast-encoded thylakoid proteins have been analysed in pulse-labeled intact chloroplasts. We show that the integration of the photosystem II reaction centre protein, D1, continues in the absence of a delta pH and in the presence of azide. A range of other proteins are similarly targeted to thylakoids in the presence of azide, suggesting that the SecA-related mechanism is not widely used for the targeting of chloroplast-encoded proteins.
authors.affiliation: Department of Biological Sciences, University of Warwick, Coventry, UK.
authors.forename: K J
authors.initials: KJ
authors.lastname: van Wijk
authors.forename: T G
authors.initials: TG
authors.lastname: Knott
authors.forename: C
authors.initials: C
authors.lastname: Robinson
mesh_terms: D000251:Adenosine Triphosphatases / Q000502:physiology; D001386:Azides / Q000494:pharmacology; D001426:Bacterial Proteins / Q000502:physiology; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006863:Hydrogen-Ion Concentration; D026901:Membrane Transport Proteins; D018532:Pisum sativum; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D019810:Sodium Azide
chemical_list: D001386:Azides; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D000069816:SEC Translocation Channels; D019810:Sodium Azide; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins