Naslov
Final step in energy conductance from thylakoid complexes to stromal reducing equivalents as a source of metabolic retrograde signals

Autori
Fulgosi, Hrvoje ; Vojta, Lea ; Jurić, Snježana ; Tomašić Paić, Ana

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

Izvornik
Abstract Book / Vothknecht, Ute ; Teige, Markus ; Rocha, Agostinho G. ; Depauw, Frauke - München : Ludwig-Maximillians Universitaet, 2011, 53-53

Skup
"Plant Organellar Signaling from Algae to Higher Plants" FEBS workshop and final symposium of the Marie-Curie ITN COSI

Mjesto i datum
Primošten, Hrvatska, 31.08.2011. - 03.09.2011

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
photosynthesis; FNR; NADPH; redox regulation

Sažetak
Working in synchrony, photosynthetic charge separation, electron transfer, and redox reactions generate proton motif force necessary for the synthesis of ATP and transport of electrons toward stromal reducing equivalent NADPH. The last step of electron transfer from ferredoxin to NADP+ is catalyzed by ubiquitous flavin adenine dinucleotide (FAD)-binding enzyme, ferredoxin-NADP+ oxidoreductase (FNR). FNR has been implicated in various thylakoid energy transduction pathways ranging from cyclic electron flow to regulation and management of oxidative stress. Two proteins, TROL (thylakoid rhodanese-like) and Tic62 (62 kDa component of the translocon at the inner envelope of chloroplasts) have been characterized and shown to form dynamic complexes with FNR. Being multi-pass membrane protein, TROL qualifies for the long-sought membrane anchor of FNR. Both TROL and Tic62 can also be found at chloroplast inner envelope, revisiting the notion of electron transfer chain specific for this compartment. Tethering of FNR to Tic62/TROL is accomplished via a conserved Ser/Pro-rich motif which forms type II alpha-helix and presumably mediates the interaction in pH-dependent manner. Inactivation of TROL leads to changes in efficiency of electron transfer and induction of non-photochemical quenching. TROL-deficient plants have changed nuclear gene expression with up-regulation of NADPH-dependent malic enzyme, which can form NADPH in an alternative pathway. Thus, NADPH synthesis, mediated by FNR-TROL interaction, may be the source element in metabolic retrograde signal-transduction pathway linking light reactions with nuclear gene expression.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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