ATG4B (human recombinant)

Autophagy-related 4B (ATG4B), also known as autophagin-1, is a cysteine protease and a member of the C54 protease family with dual roles in the progression of autophagy. It catalyzes the irreversible proteolytic cleavage of human homologs of yeast atg8 belonging to the microtubule-associated proteins 1 (MAP1)A/B-light chain 3 (LC3) and the GABA receptor-associated protein (GABARAP) subfamilies, including LC3, GATE16, GABARAP, and ATG8L, to expose a C-terminal glycine residue that is essential to formation of the autophagosome. It also catalyzes the reversible deconjugation of phosphatidylethanolamine from C-terminal glycine lipid-conjugated atg8 homologs. ATG4B expression is increased in CD34⁺ chronic myeloid leukemia (CML) stem and progenitor cells and knockdown of ATG4B expression increases accumulation of LC3-II and p62, indicating impaired autophagy, and reduces the viability and inhibits proliferation of CD34⁺ CML cells. Atg4^-/- mice exhibit systemic decreases in basal and induced autophagy as well as increased susceptibility to colitis induced by dextran sodium sulfate (DSS) and pulmonary fibrosis induced by bleomycin .

[1] MIN LI. Kinetics comparisons of mammalian Atg4 homologues indicate selective preferences toward diverse Atg8 substrates.[J]. The Journal of Biological Chemistry, 2011: 7327-7338. DOI: 10.1074/jbc.m110.199059
[2] ZHIFEN YANG. ATG4B (Autophagin-1) phosphorylation modulates autophagy.[J]. The Journal of Biological Chemistry, 2015, 290 44: 26549-26561. DOI: 10.1074/jbc.m115.658088
[3] YUKIKO KABEYA. LC3, GABARAP and GATE16 localize to autophagosomal membrane depending on form-II formation.[J]. Journal of cell science, 2004, 117 Pt 13: 2805-2812. DOI: 10.1242/jcs.01131
[4] KATHARINA ROTHE. The core autophagy protein ATG4B is a potential biomarker and therapeutic target in CML stem/progenitor cells.[J]. Blood, 2014: 3622-3634. DOI: 10.1182/blood-2013-07-516807
[5] SANDRA CABRERA. ATG4B/autophagin-1 regulates intestinal homeostasis and protects mice from experimental colitis.[J]. Autophagy, 2013, 9 8: 1188-1200. DOI: 10.4161/auto.24797
[6] SANDRA CABRERA. Essential role for the ATG4B protease and autophagy in bleomycin-induced pulmonary fibrosis.[J]. Autophagy, 2015, 11 4: 670-684. DOI: 10.1080/15548627.2015.1034409