RESUMEN
Maintenance of energy level to drive movements and material exchange with the environment is a basic principle of life. AMP-activated protein kinase (AMPK) senses energy level and is a major regulator of cellular energy responses. The gamma subunit of AMPK senses elevated ratio of AMP to ATP and allosterically activates the alpha catalytic subunit to phosphorylate downstream effectors. Here, we report that knockout of AMPKγ, but not AMPKα, suppressed phosphorylation of eukaryotic translation elongation factor 2 (eEF2) induced by energy starvation. We identified PPP6C as an AMPKγ-regulated phosphatase of eEF2. AMP-bound AMPKγ sequesters PPP6C, thereby blocking dephosphorylation of eEF2 and thus inhibiting translation elongation to preserve energy and to promote cell survival. Further phosphoproteomic analysis identified additional targets of PPP6C regulated by energy stress in an AMPKγ-dependent manner. Thus, AMPKγ senses cellular energy availability to regulate not only AMPKα kinase, but also PPP6C phosphatase and possibly other effectors.
Asunto(s)
Proteínas Quinasas Activadas por AMP , Biosíntesis de Proteínas , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Fosforilación , Factor 2 de Elongación Peptídica/metabolismoRESUMEN
BACKGROUND: Curcumin (Cur) is a natural pigment containing a diketone structure, which has attracted extensive attention due to its strong functional activities. However, the low solubility and poor stability of Cur limit its low bioavailability and multi-function. It is essential to develop effective measures to improve the unfavorable nature of Cur and maximize its potential benefits in nutritional intervention. SCOPE AND APPROACH: The focus of this review is to emphasize the construction of lipo-solubility delivery vehicles for Cur, including emulsion, nanoliposome and solid liposome. In addition, the potential benefits of vehicles-encapsulated Cur in the field of precise nutrition were summarized, including high targeting properties and multiple disease interventions. Further, the deficiencies and prospects of Cur encapsulated in vehicles for precise nutrition were discussed. KEY FINDINGS AND CONCLUSIONS: The well-designed lipo-solubility delivery vehicles for Cur can improve its stability in food processing and the digestion in vivo. To meet the nutritional requirements of special people for Cur-based products, the improvement of the bioavailability by using delivery vehicles will provide a theoretical basis for the precise nutrition of Cur in functional food.
Structural properties and bioavailability of curcumin were summarized.The practical problems and challenges in the utilization of curcumin were discussed.Various technologies for preparing lipo-solubility delivery vehicles for curcumin were described.The design of delivery vehicles for curcumin and intervention strategies in precise nutrition was reviewed.