The effect of nutrient deprivation on proteasome activity in 4-week-old mice and 24-week-old mice.

Recently, we have begun to better understand the regulatory mechanisms of proteasome activity in response to the nutritional state. In this study, we analyzed the expression and function of proteasomes in the livers and brains where changes in the metabolic system occur in vivo during short-term starvation. In the livers of 4-week-old mice, proteasome activity decreased with fasting time, whereas brain proteasome activity remained unchanged by up to 24 h of fasting and then decreased.