A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Role of serine/threonine protein kinase STN7 in the formation of two distinct photosystem I supercomplexes in Physcomitrium patens
Tekijät: Gerotto Caterina, Trotta Andrea, Bajwa Azfar Ali, Morosinotto Tomas, Aro Eva-Mari
Kustantaja: OXFORD UNIV PRESS INC
Julkaisuvuosi: 2022
Journal: Plant Physiology
Tietokannassa oleva lehden nimi: PLANT PHYSIOLOGY
Lehden akronyymi: PLANT PHYSIOL
Sivujen määrä: 16
ISSN: 0032-0889
eISSN: 1532-2548
DOI: https://doi.org/10.1093/plphys/kiac294
Verkko-osoite: https://academic.oup.com/plphys/advance-article/doi/10.1093/plphys/kiac294/6613940
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/175902498
Phosphorylation-dependent formation of photosystem I supercomplexes provides both short- and long-term acclimation of moss photosynthetic apparatus to changing environmental cues.Reversible thylakoid protein phosphorylation provides most flowering plants with dynamic acclimation to short-term changes in environmental light conditions. Here, through generating Serine/Threonine protein kinase 7 (STN7)-depleted mutants in the moss Physcomitrella (Physcomitrium patens), we identified phosphorylation targets of STN7 kinase and their roles in short- and long-term acclimation of the moss to changing light conditions. Biochemical and mass spectrometry analyses revealed STN7-dependent phosphorylation of N-terminal Thr in specific Light-Harvesting Complex II (LHCII) trimer subunits (LHCBM2 and LHCBM4/8) and provided evidence that phospho-LHCBM accumulation is responsible for the assembly of two distinct Photosystem I (PSI) supercomplexes (SCs), both of which are largely absent in STN7-depleted mutants. Besides the canonical state transition complex (PSI-LHCI-LHCII), we isolated the larger moss-specific PSI-Large (PSI-LHCI-LHCB9-LHCII) from stroma-exposed thylakoids. Unlike PSI-LHCI-LHCII, PSI-Large did not demonstrate short-term dynamics for balancing the distribution of excitation energy between PSII and PSI. Instead, PSI-Large contributed to a more stable increase in PSI antenna size in Physcomitrella, except under prolonged high irradiance. Additionally, the STN7-depleted mutants revealed altered light-dependent phosphorylation of a monomeric antenna protein, LHCB6, whose phosphorylation displayed a complex regulation by multiple kinases. Collectively, the unique phosphorylation plasticity and dynamics of Physcomitrella monomeric LHCB6 and trimeric LHCBM isoforms, together with the presence of PSI SCs with different antenna sizes and responsiveness to light changes, reflect the evolutionary position of mosses between green algae and vascular plants, yet with clear moss-specific features emphasizing their adaptation to terrestrial low-light environments.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
