Effects of ultraviolet-B light on photosystem II phosphoproteins in barley wild type and its chlorophyll b-less mutant chlorina f2.
The effects of ultraviolet-B light on the level and steady-state phosphorylation of photosystem II proteins have been studied in barley wild type and its chlorophyll b-less mutant chlorina f2. In the wild type, ultraviolet-B radiation is found to promote dephosphorylation of all thylakoid phosphoproteins. In addition, for reaction-centre proteins D1 and D2, dephosphorylation is paralleled by degradation. Photosystem II core proteins in the mutant are not found to be significantly phosphorylated in any experimental conditions, and loss of D1 and D2 reaction-centre proteins is slightly faster than in the wild type. These results are consistent with the possibility that phosphorylation of reaction-centre proteins affects their stability, possibly by slowing down the rate of degradation, as in the case of visible light.
Barbato
R
R
Dipartimento di Scienze e Tecnologie Avanzate, Università del Piemonte Orientale, Alessandria, Italy.
Bergo
E
E
Giacometti
G M
GM
D002734:Chlorophyll; D001467:Hordeum / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins / Q000378:metabolism / Q000528:radiation effects*; D016296:Mutagenesis; D010750:Phosphoproteins / Q000378:metabolism / Q000528:radiation effects*; D010766:Phosphorylation; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism / Q000528:radiation effects*; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D014466:Ultraviolet Rays
D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D010750:Phosphoproteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; C042085:thylakoid membrane phosphoprotein, plant; C021261:thylakoid polypeptides; D002734:Chlorophyll; C037184:chlorophyll b