Activating Compound | Comment | Organism | Structure |
---|---|---|---|
cytochrome b6f | activation of STN7 via binding of plastoquinol to the cytochrome b6f (Cyt b6f) complex | Arabidopsis thaliana |
General Stability | Organism |
---|---|
serine and threonine residues of plant STN7 kinase are differentially phosphorylated upon changing light conditions and specifically influence the activity and stability of the kinase | Arabidopsis thaliana |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
DTT | - |
Arabidopsis thaliana | |
additional information | the enzyme is inhibited by high light | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
thylakoid membrane | - |
Arabidopsis thaliana | 42651 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + light-harvesting complex II | Arabidopsis thaliana | - |
ADP + phospho-light-harvesting complex II | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | - |
- |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
phosphoprotein | STN7 possesses one serine, Ser526 in NALAS526ALR, and two threonine phosphosites, Thr537 and Thr541 in T537VT539ET541IDEISDGR, at the C-terminus. The latter are found in several forms, besides the nonphosphorylated and phosphorylated forms, it is found as mis-cleaved peptides on both the N-terminus (LVKTVTETIDEISDGR) and the C-terminus (TVTETIDEISDGRK). Phosphorylation of the Thr residues protects STN7 against degradation in darkness, low light and red light, whereas increasing light intensity and far red illumination decrease phosphorylation and induce STN7 degradation. Ser phosphorylation, in turn, occurs under red and low intensity white light, coinciding with the client protein (LHCII) phosphorylation. Ser526 is detected only in two forms (nonphosphorylated and phosphorylated). Ser phosphorylation and activation of the STN7 kinase for subsequent LHCII phosphorylation are heavily affected by pre-illumination conditions. Transitions between the three activity states of the STN7 kinase (deactivated in darkness and far red light, activated in low and red light, inhibited in high light) are shown to modulate the phosphorylation of the STN7 Ser and Thr residues independently of each other. Detailed of phosphorylation regulation and metabolism, overview | Arabidopsis thaliana |
Purification (Comment) | Organism |
---|---|
preparation of native thylakoids | Arabidopsis thaliana |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + light-harvesting complex II | - |
Arabidopsis thaliana | ADP + phospho-light-harvesting complex II | - |
? |
Synonyms | Comment | Organism |
---|---|---|
serine/threonine-protein kinase7 | - |
Arabidopsis thaliana |
STN7 | - |
Arabidopsis thaliana |
STN7 kinase | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ATP | - |
Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
physiological function | STN7 kinase catalyzes the phosphorylation of the globally most common membrane proteins, the light-harvesting complex II (LHCII) in plant chloroplasts. Phosphorylation of the enzyme's Thr residues protects STN7 against degradation in darkness, low light and red light, whereas increasing light intensity and far red illumination decrease phosphorylation and induce STN7 degradation. Ser phosphorylation, in turn, occurs under red and low intensity white light, coinciding with the client protein (LHCII) phosphorylation. Ser phosphorylation and activation of the STN7 kinase for subsequent LHCII phosphorylation are heavily affected by pre-illumination conditions. Transitions between the three activity states of the STN7 kinase (deactivated in darkness and far red light, activated in low and red light, inhibited in high light) are shown to modulate the phosphorylation of the STN7 Ser and Thr residues independently of each other. Such dynamic regulation of STN7 kinase phosphorylation is crucial for plant growth and environmental acclimation. Exposure of plants to high light (HL) intensities leads to LHCII dephosphorylation by phosphatase TAP38/PPH1. Detailed of phosphorylation regulation and metabolism, overview | Arabidopsis thaliana |