STN7 kinase-dependent Light-harvesting complex (LHC) protein phosphorylations in the moss Physcomitrium (Physcomitrella) patens

ABSTRACT: Photosystem (PS) I and PSII enclose the reaction center subunits and cofactors responsible for the conversion of sunlight into chemical energy. In the thylakoid membrane of oxygenic photosynthetic organisms, PSII splits the water molecules and donates electrons to the electron transfer chain, and further via PSI to form NADPH. Proteins of the light-harvesting complexes (LHC) I and II are mainly associated with PSI and PSII, respectively, but also provide dynamics for the adjustments of the absorption cross-section of PSII and PSI upon changing light conditions. LHCII proteins N-terminal phosphorylation affects their interaction either with PSI or with PSII, and is a molecular mechanism present from green algae and early land plants to higher plants. The kinase STN7 is responsible for N-terminal phosphorylation of the LHCII proteins in algae and flowering plants model species, but the specific targets and role of STN7-dependent reversible phosphorylation in formation of various PS-LHC complexes in evolutionarily early land plants like mosses is poorly studied. The aim of this project was to identify the phosphorylated residues of the LHCII subunits of the moss Physcomitrium (Physcomitrella) patens (hereafter: P. patens), i.e. the LHCBM proteins, and to determine which of the phosphosites are phosphorylated by the STN7 kinase. Subsequently, the goal has been to identify which of the LHCBM subunits that are part of PSI-LHCI-LHCII complex (state complex), and of the moss-specific PSI-Large complex, are N-terminally phosphorylated in the STN7-dependent fashion.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Physcomitrella Patens Subsp. Patens (moss)

TISSUE(S): Protonema

SUBMITTER: Andrea Trotta  

LAB HEAD: Eva-Mari Aro

PROVIDER: PXD026183 | Pride | 2022-06-24

REPOSITORIES: Pride