title: The Arabidopsis Tellurite resistance C protein together with ALB3 is involved in photosystem II protein synthesis.
abstract: Assembly of photosystem II (PSII) occurs sequentially and requires several auxiliary proteins, such as ALB3 (ALBINO3). Here, we describe the role of the Arabidopsis thaliana thylakoid membrane protein Tellurite resistance C (AtTerC) in this process. Knockout of AtTerC was previously shown to be seedling-lethal. This phenotype was rescued by expressing TerC fused C-terminally to GFP in the terc-1 background, and the resulting terc-1TerC- GFP line and an artificial miRNA-based knockdown allele (amiR-TerC) were used to analyze the TerC function. The alterations in chlorophyll fluorescence and thylakoid ultrastructure observed in amiR-TerC plants and terc-1TerC- GFP were attributed to defects in PSII. We show that this phenotype resulted from a reduction in the rate of de novo synthesis of PSII core proteins, but later steps in PSII biogenesis appeared to be less affected. Yeast two-hybrid assays showed that TerC interacts with PSII proteins. In particular, its interaction with the PSII assembly factor ALB3 has been demonstrated by co-immunoprecipitation. ALB3 is thought to assist in incorporation of CP43 into PSII via interaction with Low PSII Accumulation2 (LPA2) Low PSII Accumulation3 (LPA3). Homozygous lpa2 mutants expressing amiR-TerC displayed markedly exacerbated phenotypes, leading to seedling lethality, indicating an additive effect. We propose a model in which TerC, together with ALB3, facilitates de novo synthesis of thylakoid membrane proteins, for instance CP43, at the membrane insertion step.
authors.affiliation: Molekularbiologie der Pflanzen (Botanik), Department Biologie I, Ludwig Maximilians Universität München, 82152, Martinsried, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Schneider
authors.forename: Iris
authors.initials: I
authors.lastname: Steinberger
authors.forename: Henning
authors.initials: H
authors.lastname: Strissel
authors.forename: Hans-Henning
authors.initials: HH
authors.lastname: Kunz
authors.forename: Nikolay
authors.initials: N
authors.lastname: Manavski
authors.forename: Jörg
authors.initials: J
authors.lastname: Meurer
authors.forename: Gabi
authors.initials: G
authors.lastname: Burkhard
authors.forename: Sabine
authors.initials: S
authors.lastname: Jarzombski
authors.forename: Danja
authors.initials: D
authors.lastname: Schünemann
authors.forename: Stefan
authors.initials: S
authors.lastname: Geimer
authors.forename: Ulf-Ingo
authors.initials: UI
authors.lastname: Flügge
authors.forename: Dario
authors.initials: D
authors.lastname: Leister
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010641:Phenotype; D045332:Photosystem II Protein Complex / Q000096:biosynthesis*; D020524:Thylakoids / Q000378:metabolism
chemical_list: C106404:ALBINO 3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D045332:Photosystem II Protein Complex; C532385:TerC protein, Arabidopsis
keywords: ALB3; Arabidopsis thaliana; AtTerC; assembly; photosystem II; thylakoid membrane