| 背景 | Cysteine protease ATG4B is a ~44 kDa protein. Cysteine protease that plays a key role in autophagy by mediating both proteolytic activation and delipidation of ATG8 family proteins. Required for canonical autophagy (macroautophagy), non-canonical autophagy as well as for mitophagy. The protease activity is required for proteolytic activation of ATG8 family proteins: cleaves the C-terminal amino acid of ATG8 proteins MAP1LC3A, MAP1LC3B, MAP1LC3C, GABARAPL1, GABARAPL2 and GABARAP, to reveal a C-terminal glycine. Exposure of the glycine at the C-terminus is essential for ATG8 proteins conjugation to phosphatidylethanolamine (PE) and insertion to membranes, which is necessary for autophagy. Protease activity is also required to counteract formation of high-molecular weight conjugates of ATG8 proteins (ATG8ylation): acts as a deubiquitinating-like enzyme that removes ATG8 conjugated to other proteins, such as ATG3. 1. Kabeya, Y. et al. (2004) Journal of cell science 117, 2805-12. PMID: 151698372. Tanida, I. et al. (2004) The Journal of biological chemistry 279, 36268-76. PMID: 151870943. Scherz-Shouval, R. et al. (2007) The EMBO journal 26, 1749-60. PMID: 173476514. Satoo, K. et al. (2009) The EMBO journal 28, 1341-50. PMID: 193221945. Li, M. et al. (2011) The Journal of biological chemistry 286, 7327-38. PMID: 211778657. Yang, Z. et al. (2015) The Journal of biological chemistry 290, 26549-61. PMID: 2637824110. Pengo, N. et al. (2017) Nature communications 8, 294. PMID: 28821708 |
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