Naslov
Dual localization of TROL: defining and substituting chloroplast import determinants

Autori
Vojta, Lea ; Čuletić, Andrea ; Fulgosi, Hrvoje

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

Izvornik
COST15133 : Book of Abstracts / - , 2018, 9-9

Skup
3rd meeting of the COST action CA15133 "The Biogenesis of Iron-sulfur Proteins: from Cellular Biology to Molecular Aspects"(FeSBioNet)

Mjesto i datum
Zagreb, Hrvatska, 11.06.2018. - 14.06.2018

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
TROL ; FNR ; Thylakoids ; Protein import ; Sorting

Sažetak
TROL (thylakoid rhodanese-like protein) has been discovered relatively recently as an integral membrane component associated to the photosynthetic apparatus of higher plants. TROL is involved in the final step of photosynthetic electron transport by binding a key energy-conversion enzyme ferredoxin:NADP+ oxidoreductase (FNR). This interaction enables direct transfer of photosynthetic electrons from iron-sulphur protein ferredoxin at the stromal site of photosystem I to FNR, which then hands over electrons to NADP+. TROL is located in two distinct chloroplast compartments – in the inner envelope of chloroplasts, in its precursor form ; and in the thylakoid membranes, where it is processed completely. The determinants for its different localization have not been resolved yet, along with its role in the inner envelope. N-terminal presequence directs TROL from the site of its synthesis in cytosol to the chloroplasts. We created six N-terminal amino acid substitutions surrounding the predicted presequence processing site of TROL in order to interfere with import and to obtain a construct whose localization is limited to a single intrachloroplastic site. Wild type precursor of TROL and its e1-e6 presequence mutants were labelled with [35S]-methionine during in vitro translation and imported into isolated intact pea chloroplasts under various conditions. Time and energy requirements for acquiring a final localization have been monitored. Also, by using different extraction methods the strength of protein to membrane association has been determined. We found that a single amino acid exchange in the presequence, Ala67 to Ile67 interferes with processing of the protein in the stroma and directs the whole pool of in vitro translated TROL to the single subchloroplastic compartment - the inner envelope. This result opens a possibility to engineer plants with a single protein localization site in an attempt to study the function of TROL in the chloroplast inner envelope, as well as possible consequence/s of its absence from the thylakoids.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA