Identification of a Photosystem II Phosphatase Involved in Light Acclimation in Arabidopsis
2012 (English)In: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 24, no 6, 2596-2609 p.Article in journal (Refereed) Published
Reversible protein phosphorylation plays a major role in the rapid acclimation of the photosynthetic apparatus to changes in light. Two paralogous kinases phosphorylate subsets of thylakoid membrane proteins. STN7 phosphorylates LHCII, the light harvesting antenna of photosystem II (PSII), to balance the activity of the two photosystems through state transitions. STN8 which is mainly involved in phosphorylation of PSII influences folding of the thylakoid membranes and repair of PSII after photo-damage. The rapid reversibility of these acclimatory responses requires the action of protein phosphatases.
In a reverse genetic screen we have identified the chloroplast PP2C phosphatase, PBCP (PHOTOSYSTEM II CORE PHOSPHATASE), which is required for efficient dephosphorylation of PSII. Its targets identified by immunoblotting and mass spectrometry largely coincide with those of the kinase STN8. The recombinant phosphatase is active in vitro on a synthetic substrate or on isolated thylakoids. Thylakoid folding and degradation of D1 after photo-damage are affected in the absence of PBCP, while its over-expression alters the kinetics of state transitions. PBCP and STN8 form an antagonistic kinase and phosphatase pair whose substrate specificity and physiological function are distinct from those of STN7 and the counteracting phosphatase PPH1 (TAP38), but their activities may overlap to some degree.
Place, publisher, year, edition, pages
2012. Vol. 24, no 6, 2596-2609 p.
IdentifiersURN: urn:nbn:se:liu:diva-76725DOI: 10.3410/f.717847818.793153384ISI: 000306919300027OAI: oai:DiVA.org:liu-76725DiVA: diva2:516428
On the day of the defence date the title of the article was The role of PHOTOSYSTEM II CORE PHOSPHATASE in light acclimation of photosynthesis in Arabidopsis.
Funding agencies|SystemsX.ch (RTD Plant Growth in a Changing Environment)||Swiss National Foundation|3100AO-11771231003A_133089/1|FP7 Marie-Curie Initial Training Network (ITN) COSI|ITN 2008 GA 215-174|EMBO postdoctoral fellowship||Swedish Research Council|2008-5490|2012-04-182012-04-182012-08-30Bibliographically approved