Naslov
Molecular basis of alternative electron partitioning in photosynthesis

Autori
Fulgosi, Hrvoje ; Vojta, Lea

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts of the FEBS3+ Meeting "Molecules of Life" / Kos, Janko ; Poklar Ulrih, Nataša - Ljubljana : Slovenian Biochemical Society, 2015, 50-50

ISBN
978-961-93879-0-0

Skup
Molecules of Life: FEBS3+ Meeting and 11th Meeting of the Slovenian Biochemical Society

Mjesto i datum
Portorož, Slovenija, 16.09.2015. - 19.09.2015

Vrsta sudjelovanja
Plenarno

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
photosystem I; redox regulation and signaling; regulation of electron flow

Sažetak
In vascular plant photosynthesis several electron transport chains have been recognized. Linear electron transport chain (LET) transfers electrons generated by photosystems II and I to a small iron-sulphur protein ferredoxin (Fd). Fd acts simultaneously as a bottleneck and as a hub which distributes high-energy electrons to a multitude of enzymes. The dominant pathway in chloroplasts is, however, the one that produces NADPH, by the activity of ferredoxin-NADP+-oxidoreductase (FNR). FNR is a soluble protein that exists in several isoforms and utilizes two reduced Fds to produce one molecule of NADPH. In order to function efficiently Fd/FNR redox chemistry has to be constantly poised. The question remains how is the partitioning of electrons between various energy-conserving and -dissipating pathways achieved. We have previously shown that thylakoid rhodanase-like protein TROL acts as a bona fide membrane attachment point for the FNR, although other associations with thylakoid and inner envelope membranes have been described. We have proposed a scheme for the dynamic FNR recruitment to TROL. We posit that TROL-FNR interaction represents branching point between electron-conserving and electron-dissipating pathways. Without the TROL, light-dependent O2.- generation is reduced, while the generation of other ROS is enhanced. We propose that other Fd-dependent pathways downstream of PSI and different from the linear electron transfer become dominant by the dynamic detachment of FNR form TROL, thus suggesting a novel mechanism of photosynthesis regulation. Alternatively, efficient scavenging of O2.- by FNR-dependent pathways can be envisaged.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA