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Microautophagy (unlike Macroautophagy and Chaperone-mediated autophagy) is the type of autophagic pathway which is mediated by direct lysosomal (mammals) or vacuolar (plants and fungi) engulfment of the cytoplasmic cargo. Cytoplasmic material is trapped in the lysosome/vacuole by the random process of membrane invagination. Microautophagic pathway is especially important for survival of cells under starvation, nitrogen deprivation or after treatment with rapamycin. Microautophagy generally is a non-selective process but there are 3 special cases of selective microautophagic pathway (micropexophagy, Piecemeal microautophagy of the nucleus, micromitophagy) which are activated under a specific conditions. == Functions of microautophagy == Microautophagy together with macroautophagy is necessary for nutrient recycling under starvation. Microautophagy due to degradation of lipids incorporated into vesicles regulates the composition of lysosomal/vacuolar membrane.〔 Microautophagic pathway functions also as one of the mechanism of glycogen delivery into the lysosomes. This autophagic pathway engulfs multivesicular bodies formed after endocytosis therefore it plays role in membrane proteins turnover. Microautophagy is also connected with organellar size maintenance, composition of biological membranes, cell survival under nitrogen restriction, and the transition pathway from starvation-induced growth arrest to logarithmic growth.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Microautophagy」の詳細全文を読む スポンサード リンク
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