Dynamics of reversible protein phosphorylation in thylakoids of flowering plants: The roles of STN7, STN8 and TAP38

• Published in: Biochimica et biophysica acta Vol. 1807; no. 8; pp. 887 - 896
• Main Authors: Pesaresi, Paolo, Pribil, Mathias, Wunder, Tobias, Leister, Dario
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2011
• Subjects: Acclimation; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; dephosphorylation; electron transfer; energy; environmental factors; Light; light harvesting complex; Light-Harvesting Protein Complexes - genetics; Light-Harvesting Protein Complexes - metabolism; lighting; membrane proteins; Phosphoprotein Phosphatases - genetics; Phosphoprotein Phosphatases - metabolism; phosphoproteins; Phosphorylation - physiology; Phosphorylation - radiation effects; Photosynthesis; Photosystem I Protein Complex - genetics; Photosystem I Protein Complex - metabolism; photosystem II; Photosystem II Protein Complex - genetics; Photosystem II Protein Complex - metabolism; post-translational modification; protein kinases; Protein Kinases - genetics; Protein Kinases - metabolism; protein phosphorylation; Protein-Serine-Threonine Kinases; Regulation; State transitions; thylakoids; Thylakoids - enzymology; Thylakoids - genetics; ultrastructure; STN7/STN8; TAP38/PPH1; LHCII; State transitions; Regulation; LTR; Photosynthesis; Acclimation
• ISSN: 0005-2728; 0006-3002; 1879-2650
• DOI: 10.1016/j.bbabio.2010.08.002

Phosphorylation is the most common post-translational modification found in thylakoid membrane proteins of flowering plants, targeting more than two dozen subunits of all multiprotein complexes, including some light-harvesting proteins. Recent progress in mass spectrometry-based technologies has led to the detection of novel low-abundance thylakoid phosphoproteins and localised their phosphorylation sites. Three of the enzymes involved in phosphorylation/dephosphorylation cycles in thylakoids, the protein kinases STN7 and STN8 and the phosphatase TAP38/PPH1, have been characterised in the model species Arabidopsis thaliana. Differential protein phosphorylation is associated with changes in illumination and various other environmental parameters, and has been implicated in several acclimation responses, the molecular mechanisms of which are only partly understood. The phenomenon of State Transitions, which enables rapid adaptation to short-term changes in illumination, has recently been shown to depend on reversible phosphorylation of LHCII by STN7-TAP38/PPH1. STN7 is also necessary for long-term acclimation responses that counteract imbalances in energy distribution between PSII and PSI by changing the rates of accumulation of their reaction-centre and light-harvesting proteins. Another aspect of photosynthetic acclimation, the modulation of thylakoid ultrastructure, depends on phosphorylation of PSII core proteins, mainly executed by STN8. Here we review recent advances in the characterisation of STN7, STN8 and TAP38/PPH1, and discuss their physiological significance within the overall network of thylakoid protein phosphorylation. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts. ►Mass spectrometry and genetic approaches have advanced the field of thylakoid protein phosphorylation research. ►28 thylakoid proteins have been identified so far to be subject to phosphorylation. ►Two protein kinases (STN7 and STN8) and one phosphatase (TAP38/PPH1) involved in thylakoid protein phosphorylation have been identified. ►Reversible LHCII phosphorylation is the best understood instance of thylakoid protein phosphorylation. ►Only for very phosphoproteins the physiological significance of reversible phosphorylation has been elucidated.