What are the key proteins involved in autophagy?-January 2024-www.zdask.com

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Definition: What are the key proteins involved in autophagy?

Autophagy is a cellular process that involves the degradation and recycling of cellular components, such as damaged organelles and proteins, to maintain cellular homeostasis. This process is crucial for cellular survival, especially during times of nutrient deprivation or stress.

Several key proteins play essential roles in the regulation and execution of autophagy. These proteins can be categorized into three main groups: initiation proteins, elongation proteins, and fusion proteins.

1. Initiation proteins:

– ULK1/2 (Unc-51-like kinase 1/2): These serine/threonine kinases are essential for autophagy initiation. They are responsible for the formation of the autophagy initiation complex, which includes other proteins such as ATG13 and FIP200.

– VPS34 (vacuolar protein sorting 34): This class III phosphatidylinositol 3-kinase complex is involved in the nucleation of the autophagosome, the double-membrane structure that engulfs cellular components targeted for degradation.

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2. Elongation proteins:

– ATG5-ATG12: This protein complex is essential for the elongation of the autophagosomal membrane. It promotes the conjugation of ATG8/LC3 (microtubule-associated protein 1A/1B-light chain 3) to phosphatidylethanolamine (PE), which is crucial for autophagosome formation.

– ATG7: This E1-like enzyme is responsible for the activation of ATG12 and ATG8/LC3, facilitating their conjugation to their respective targets.

– ATG9: This transmembrane protein is involved in the delivery of membrane components to the growing autophagosome.

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3. Fusion proteins:

– SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors): These proteins mediate the fusion of the autophagosome with lysosomes, forming the autolysosome. Syntaxin 17 (STX17) and SNAP29 are examples of SNAREs involved in autophagy fusion.

These key proteins work together in a highly regulated manner to ensure the proper execution of autophagy. Dysregulation of any of these proteins can lead to impaired autophagy, which has been implicated in various diseases, including neurodegenerative disorders and cancer.

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Keywords: proteins, autophagy, cellular, protein, involved, initiation, fusion, autophagosome, components