title: Efficient assembly of photosystem II in Chlamydomonas reinhardtii requires Alb3.1p, a homolog of Arabidopsis ALBINO3.
abstract: Alb3 homologs Oxa1 and YidC have been shown to be required for the integration of newly synthesized proteins into membranes. Here, we show that although Alb3.1p is not required for integration of the plastid-encoded photosystem II core subunit D1 into the thylakoid membrane of Chlamydomonas reinhardtii, the insertion of D1 into functional photosystem II complexes is retarded in the Alb3.1 deletion mutant ac29. Alb3.1p is associated with D1 upon its insertion into the membrane, indicating that Alb3.1p is essential for the efficient assembly of photosystem II. Furthermore, levels of nucleus-encoded light-harvesting proteins are vastly reduced in ac29; however, the remaining antenna systems are still connected to photosystem II reaction centers. Thus, Alb3.1p has a dual function and is required for the accumulation of both nucleus- and plastid-encoded protein subunits in photosynthetic complexes of C. reinhardtii.
authors.affiliation: Department for Biology I, Ludwig-Maximilians-University Munich, D-80638, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Ossenbühl
authors.forename: Vera
authors.initials: V
authors.lastname: Göhre
authors.forename: Jörg
authors.initials: J
authors.lastname: Meurer
authors.forename: Anja
authors.initials: A
authors.lastname: Krieger-Liszkay
authors.forename: Jean-David
authors.initials: JD
authors.lastname: Rochaix
authors.forename: Lutz A
authors.initials: LA
authors.lastname: Eichacker
mesh_terms: D000818:Animals; D029681:Arabidopsis Proteins / Q000235:genetics; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism; D009154:Mutation; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D017384:Sequence Deletion; D020524:Thylakoids / Q000378:metabolism
chemical_list: C106404:ALBINO 3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex