This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/1/369    most recent tpc.106.044404v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend 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 ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Pruzinská, A. Articles by Hörtensteiner, S. Search for Related Content PubMed PubMed Citation Articles by Pruzinská, A. Articles by Hörtensteiner, S. Agricola Articles by Pruzinská, A. Articles by Hörtensteiner, S.

In Vivo Participation of Red Chlorophyll Catabolite Reductase in Chlorophyll Breakdown^[W]

Adriana Pruinská^a,1,2, Iwona Anders^a,1, Sylvain Aubry^a, Nicole Schenk^a, Esther Tapernoux-Lüthi^b, Thomas Müller^c, Bernhard Kräutler^c and Stefan Hörtensteiner^a,3

^a Institute of Plant Sciences, University of Bern, CH-3013 Bern, Switzerland
^b Institute of Plant Biology, University of Zürich, CH-8008 Zürich, Switzerland
^c Institute of Organic Chemistry and Center of Molecular Biosciences, Leopold-Franzens-University Innsbruck, A-6020 Innsbruck, Austria

³ To whom correspondence should be addressed. E-mail shorten{at}ips.unibe.ch; fax 41-31-631-49-42.

A central reaction of chlorophyll breakdown, porphyrin ring opening of pheophorbide a to the primary fluorescent chlorophyll catabolite (pFCC), requires pheophorbide a oxygenase (PAO) and red chlorophyll catabolite reductase (RCCR), with red chlorophyll catabolite (RCC) as a presumably PAO-bound intermediate. In subsequent steps, pFCC is converted to different fluorescent chlorophyll catabolites (FCCs) and nonfluorescent chlorophyll catabolites (NCCs). Here, we show that RCCR-deficient Arabidopsis thaliana accumulates RCC and three RCC-like pigments during senescence, as well as FCCs and NCCs. We also show that the stereospecificity of Arabidopsis RCCR is defined by a small protein domain and can be reversed by a single Phe-to-Val exchange. Exploiting this feature, we prove the in vivo participation of RCCR in chlorophyll breakdown. After complementation of RCCR mutants with RCCRs exhibiting alternative specificities, patterns of chlorophyll catabolites followed the specificity of complementing RCCRs. Light-dependent leaf cell death observed in different RCCR-deficient lines strictly correlated with the accumulation of RCCs and the release of singlet oxygen, and PAO induction preceded lesion formation. These findings suggest that RCCR absence causes leaf cell death as a result of the accumulation of photodynamic RCC. We conclude that RCCR (together with PAO) is required for the detoxification of chlorophyll catabolites and discuss the biochemical role(s) for this enzyme.

This article has been cited by other articles:

				N. A. Eckardt Thylakoid Development from Biogenesis to Senescence, and Ruminations on Regulation PLANT CELL, April 1, 2007; 19(4): 1135 - 1138. [Full Text] [PDF]

				S. Harpaz-Saad, T. Azoulay, T. Arazi, E. Ben-Yaakov, A. Mett, Y. M. Shiboleth, S. Hortensteiner, D. Gidoni, A. Gal-On, E. E. Goldschmidt, et al. Chlorophyllase Is a Rate-Limiting Enzyme in Chlorophyll Catabolism and Is Posttranslationally Regulated PLANT CELL, March 1, 2007; 19(3): 1007 - 1022. [Abstract] [Full Text] [PDF]