Recombinant Arabidopsis thaliana Uncharacterized aarF domain-containing protein kinase At4g31390, chloroplastic (At4g31390), partial

Kinase that can phosphorylate the tocopherol cyclase VTE1, a key enzyme of tocopherol (vitamin E) metabolism and involved in the recycling of oxidated alpha-tocopherol quinone, possibly stabilizing it at plastoglobules. Regulates also plastoglobule protein composition. Prevents photodamage of chloroplasts under continuous red light, thus working in opposition to ABC1K3. Together with ABC1K1, contributes to plastoglobule (PG) function in prenyl-lipid metabolism, stress response, and thylakoid remodeling. Involved in chlorophyll degradation and in the maintenance of the number of chlorophyll-binding photosynthetic thylakoid membranes. Ensures photosynthetic electron transport by regulating the homeostasis of plastoquinone, beta-carotene and xanthophyll lutein, as well as membrane antioxidant tocopherol metabolism. Seems to affect specifically stability or turnover of D1 protein, product of psbA, one of the four core subunits of the photosystem II (PSII). Required for photooxidative stress responses, including the induction of oxidative stress response genes (e.g. FSD1, CSD1, CAT1, and UTG71C1), to prevent photosystem II core and chlorophyll degradations.