Constitutive autophagy protects from neurodegeneration

Yoshinobu Ichimura¹⁾, Masaaki Komatsu²⁾

¹⁾Department of Biochemistry, Juntendo University School of Medicine
²⁾Laboratory of Frontier Science, Tokyo Metropolitan Institute of Medical Science

Autophagy is a highly conserved bulk protein degradation pathway in eukaryotes. Emerging evidence emphasizes the importance of autophagy in various biological and pathological processes, such as cellular remodelling, tumorigenesis and developmental programmes. Recent evidence indicates that in mammalian cells, autophagy serves two physiological purposes. The first is to supply amino acids for cell survival under poor-environmental conditions, which is universally known as ‘adaptive autophagy'. The second is to degrade proteins in the cell through continuous operation at a low level irrespective of nutritional stress, known as ‘basal or constitutive autophagy'. In the latter pathway, autophagy is responsible for the turnover of long-lived proteins, disposal of excess or damaged organelles, and clearance of aggregate-prone proteins. In this review, we introduce the important roles of constitutive autophagy in protection against neurodegeneration as well as its molecular mechanism.

Address correspondence to Dr. Masaaki Komatsu, Laboratory of Frontier Science, Tokyo Metropolitan Institute of Medical Science (Bunkyo-ku, Tokyo, Japan)