This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/4/1313    most recent tpc.106.049270v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Plant Cell Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Miura, E. Articles by Sakamoto, W. Search for Related Content PubMed PubMed Citation Articles by Miura, E. Articles by Sakamoto, W. Agricola Articles by Miura, E. Articles by Sakamoto, W.

The Balance between Protein Synthesis and Degradation in Chloroplasts Determines Leaf Variegation in Arabidopsis yellow variegated Mutants^[W]

^a Research Institute for Bioresources, Okayama University, Kurashiki, Okayama 710-0046, Japan
^b Institute of Plant Sciences, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland
^c Institut Jacques Monod, Centre National de la Recherche Scientifique, Universités Paris 6 et Paris 7, 75251 Paris, France

² To whom correspondence should be addressed. E-mail saka{at}rib.okayama-u.ac.jp; fax 81-86-434-1206.

An Arabidopsis thaliana leaf-variegated mutant yellow variegated2 (var2) results from loss of FtsH2, a major component of the chloroplast FtsH complex. FtsH is an ATP-dependent metalloprotease in thylakoid membranes and degrades several chloroplastic proteins. To understand the role of proteolysis by FtsH and mechanisms leading to leaf variegation, we characterized the second-site recessive mutation fu-gaeri1 (fug1) that suppressed leaf variegation of var2. Map-based cloning and subsequent characterization of the FUG1 locus demonstrated that it encodes a protein homologous to prokaryotic translation initiation factor 2 (cpIF2) located in chloroplasts. We show evidence that cpIF2 indeed functions in chloroplast protein synthesis in vivo. Suppression of leaf variegation by fug1 is observed not only in var2 but also in var1 (lacking FtsH5) and var1 var2. Thus, suppression of leaf variegation caused by loss of FtsHs is most likely attributed to reduced protein synthesis in chloroplasts. This hypothesis was further supported by the observation that another viable mutation in chloroplast translation elongation factor G also suppresses leaf variegation in var2. We propose that the balance between protein synthesis and degradation is one of the determining factors leading to the variegated phenotype in Arabidopsis leaves.

Related articles in Plant Cell:

Thylakoid Development from Biogenesis to Senescence, and Ruminations on Regulation

Nancy A. Eckardt
Plant Cell 2007 19: 1135-1138. [Full Text]  

This article has been cited by other articles:

				L. Y. Tang, N. Nagata, R. Matsushima, Y. Chen, Y. Yoshioka, and W. Sakamoto Visualization of Plastids in Pollen Grains: Involvement of FtsZ1 in Pollen Plastid Division Plant Cell Physiol., April 1, 2009; 50(4): 904 - 908. [Abstract] [Full Text] [PDF]

				F. Yu, X. Liu, M. Alsheikh, S. Park, and S. Rodermel Mutations in SUPPRESSOR OF VARIEGATION1, a Factor Required for Normal Chloroplast Translation, Suppress var2-Mediated Leaf Variegation in Arabidopsis PLANT CELL, July 1, 2008; 20(7): 1786 - 1804. [Abstract] [Full Text] [PDF]

				K. Yoshida, C. Watanabe, Y. Kato, W. Sakamoto, and K. Noguchi Influence of Chloroplastic Photo-Oxidative Stress on Mitochondrial Alternative Oxidase Capacity and Respiratory Properties: A Case Study with Arabidopsis yellow variegated 2 Plant Cell Physiol., April 1, 2008; 49(4): 592 - 603. [Abstract] [Full Text] [PDF]