TY  - JOUR
A1  - Mettler, Tabea
A1  - Mühlhaus, Timo
A1  - Hemme, Dorothea
A1  - Schöttler, Mark Aurel
A1  - Rupprecht, Jens
A1  - Idoine, Adam
A1  - Veyel, Daniel
A1  - Pal, Sunil Kumar
A1  - Yaneva-Roder, Liliya
A1  - Winck, Flavia Vischi
A1  - Sommer, Frederik
A1  - Vosloh, Daniel
A1  - Seiwert, Bettina
A1  - Erban, Alexander
A1  - Burgos, Asdrubal
A1  - Arvidsson, Samuel Janne
A1  - Schoenfelder, Stephanie
A1  - Arnold, Anne
A1  - Guenther, Manuela
A1  - Krause, Ursula
A1  - Lohse, Marc
A1  - Kopka, Joachim
A1  - Nikoloski, Zoran
A1  - Müller-Röber, Bernd
A1  - Willmitzer, Lothar
A1  - Bock, Ralph
A1  - Schroda, Michael
A1  - Stitt, Mark
T1  - Systems analysis of the response of photosynthesis, metabolism, and growth to an increase in irradiance in the photosynthetic model organism chlamydomonas reinhardtii
JF  - The plant cell
N2  - We investigated the systems response of metabolism and growth after an increase in irradiance in the nonsaturating range in the algal model Chlamydomonas reinhardtii. In a three-step process, photosynthesis and the levels of metabolites increased immediately, growth increased after 10 to 15 min, and transcript and protein abundance responded by 40 and 120 to 240 min, respectively. In the first phase, starch and metabolites provided a transient buffer for carbon until growth increased. This uncouples photosynthesis from growth in a fluctuating light environment. In the first and second phases, rising metabolite levels and increased polysome loading drove an increase in fluxes. Most Calvin-Benson cycle (CBC) enzymes were substrate-limited in vivo, and strikingly, many were present at higher concentrations than their substrates, explaining how rising metabolite levels stimulate CBC flux. Rubisco, fructose-1,6-biosphosphatase, and seduheptulose-1,7-bisphosphatase were close to substrate saturation in vivo, and flux was increased by posttranslational activation. In the third phase, changes in abundance of particular proteins, including increases in plastidial ATP synthase and some CBC enzymes, relieved potential bottlenecks and readjusted protein allocation between different processes. Despite reasonable overall agreement between changes in transcript and protein abundance (R-2 = 0.24), many proteins, including those in photosynthesis, changed independently of transcript abundance.
Y1  - 2014
U6  - https://doi.org/10.1105/tpc.114.124537
SN  - 1040-4651
SN  - 1532-298X
VL  - 26
IS  - 6
SP  - 2310
EP  - 2350
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  - 
TY  - JOUR
A1  - Nordhues, Andre
A1  - Schöttler, Mark Aurel
A1  - Unger, Ann-Katrin
A1  - Geimer, Stefan
A1  - Schönfelder, Stephanie
A1  - Schmollinger, Stefan
A1  - Ruetgers, Mark
A1  - Finazzi, Giovanni
A1  - Soppa, Barbara
A1  - Sommer, Frederik
A1  - Mühlhaus, Timo
A1  - Roach, Thomas
A1  - Krieger-Liszkay, Anja
A1  - Lokstein, Heiko
A1  - Luis Crespo, Jose
A1  - Schroda, Michael
T1  - Evidence for a role of VIPP1 in the structural organization of the photosynthetic apparatus in chlamydomonas
JF  - The plant cell
N2  - The vesicle-inducing protein in plastids (VIPP1) was suggested to play a role in thylakoid membrane formation via membrane vesicles. As this functional assignment is under debate, we investigated the function of VIPP1 in Chlamydomonas reinhardtii. Using immunofluorescence, we localized VIPP1 to distinct spots within the chloroplast. In VIPP1-RNA interference/artificial microRNA cells, we consistently observed aberrant, prolamellar body-like structures at the origin of multiple thylakoid membrane layers, which appear to coincide with the immunofluorescent VIPP1 spots and suggest a defect in thylakoid membrane biogenesis. Accordingly, using quantitative shotgun proteomics, we found that unstressed vipp1 mutant cells accumulate 14 to 20% less photosystems, cytochrome b(6)f complex, and ATP synthase but 30% more light-harvesting complex II than control cells, while complex assembly, thylakoid membrane ultrastructure, and bulk lipid composition appeared unaltered. Photosystems in vipp1 mutants are sensitive to high light, which coincides with a lowered midpoint potential of the Q(A)/Q(A)(-) redox couple and increased thermosensitivity of photosystem II (PSII), suggesting structural defects in PSII. Moreover, swollen thylakoids, despite reduced membrane energization, in vipp1 mutants grown on ammonium suggest defects in the supermolecular organization of thylakoid membrane complexes. Overall, our data suggest a role of VIPP1 in the biogenesis/assembly of thylakoid membrane core complexes, most likely by supplying structural lipids.
Y1  - 2012
U6  - https://doi.org/10.1105/tpc.111.092692
SN  - 1040-4651
VL  - 24
IS  - 2
SP  - 637
EP  - 659
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  -