Autophagy

Autophagy or autophagy is a cell function, are degraded in a similar phagocytosis components of a cell. Phagocytosis itself refers to the degradation of substances out of the cell, such as proteins, membranes and other cellular structures. Autophagy is the same process, but the cell is building its own ingredients from. This ranges from misfolded proteins to large cell organelles. The process itself is necessary for a balance between production and degradation of new age cell components. A mitochondrion of a liver cell has, for example, a "lifetime" of ten days prior to being degraded by autophagy and its components be re-used for the construction of other structures (see Mitophagie ). Autophagy occurs in many eukaryotes, such as plants, multicellular animals, slime molds and yeasts.

Autophagy also allows the elimination of viruses, bacteria and foreign proteins that accumulate in the cell. It is thus also in the immune response. In insects, the process used to convert the larval tissue into the adult form. Here, the fabric is melted down and rearranged to the adult animal during pupation. There are two signals that trigger this process: a lack of nutrients leads to the degradation of non-essential cell components. For over vital processes continue to be supplied with energy. Oversupply of nutrients can trigger autophagy. Now, new organelles are formed by the excess energy and old reused.

Autophagy can also cause the death of the cells. It is part of programmed cell death ( apoptosis, autophagic cell death ). It thus regulates the growth of multicellular organisms and colonies ( yeast).

One divides the process into three groups: Makroautophagozytose, Mikroautophagozytose and Chaperone mediated autophagy (CMA ).

In Makroautophagozytose encloses a part of the membrane of the endoplasmic reticulum marked for degradation structures, after which this combined with a lysosome. In the Mikroautophagozytose a lysosome directly encloses the degraded structures. The Chaperone mediated autophagy (CMA ) proteins are detected with a KFERQ - like motif of Hsp70 chaperones and led to the lysosome, where they pass through the lysosomal membrane -associated protein 2 (LAMP -2A ) into the lysosome and are degraded.