PGRL1 participates in iron-induced remodeling of the photosynthetic apparatus and in energy metabolism in Chlamydomonas reinhardtii.
PGRL1 RNA and protein levels are increased in iron-deficient Chlamydomonas reinhardtii cells. In an RNAi strain, which accumulates lower PGRL1 levels in both iron-replete and -starved conditions, the photosynthetic electron transfer rate is decreased, respiratory capacity in iron-sufficient conditions is increased, and the efficiency of cyclic electron transfer under iron-deprivation is diminished. Pgrl1-kd cells exhibit iron deficiency symptoms at higher iron concentrations than wild-type cells, although the cells are not more depleted in cellular iron relative to wild-type cells as measured by mass spectrometry. Thiol-trapping experiments indicate iron-dependent and redox-induced conformational changes in PGRL1 that may provide a link between iron metabolism and the partitioning of photosynthetic electron transfer between linear and cyclic flow. We propose, therefore, that PGRL1 in C. reinhardtii may possess a dual function in the chloroplast; that is, iron sensing and modulation of electron transfer.
Institute of Plant Biochemistry and Biotechnology, University of Münster, Hindenburgplatz 55, 48143 Münster, Germany.
Dimitris
D
Petroutsos
Aimee M
AM
Terauchi
Andreas
A
Busch
Ingrid
I
Hirschmann
Sabeeha S
SS
Merchant
Giovanni
G
Finazzi
Michael
M
Hippler
D002352:Carrier Proteins / Q000737:chemistry / Q000502:physiology*; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D004583:Electrons; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D008565:Membrane Proteins / Q000737:chemistry; D010084:Oxidation-Reduction; D010788:Photosynthesis; D011487:Protein Conformation; D012313:RNA / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013438:Sulfhydryl Compounds; D013696:Temperature; D020524:Thylakoids / Q000737:chemistry
D002352:Carrier Proteins; D008565:Membrane Proteins; D013438:Sulfhydryl Compounds; D012313:RNA; D007501:Iron