| IED ID | IndEnz0002014406 |
| Enzyme Type ID | protease014406 |
| Protein Name |
Cysteine protease ATG4B EC 3.4.22.- Autophagy-related protein 4 homolog B |
| Gene Name | atg4b apg4b |
| Organism | Xenopus laevis (African clawed frog) |
| Taxonomic Lineage | cellular organisms Eukaryota Opisthokonta Metazoa Eumetazoa Bilateria Deuterostomia Chordata Craniata Vertebrata Gnathostomata (jawed vertebrates) Teleostomi Euteleostomi Sarcopterygii Dipnotetrapodomorpha Tetrapoda Amphibia Batrachia Anura Pipoidea Pipidae Xenopodinae Xenopus Xenopus Xenopus laevis (African clawed frog) |
| Enzyme Sequence | MDAATLTYDTLRFADTPDFPETAEPVWVLGRKYSALTEKEQLLNDITSRLWFTYRRNFQAIGGTGPTSDTGWGCMLRCGQMIFAQALICRHVGRDWRWDKQKPKGEYLNILTAFLDKKDSYYSIHQIAQMGVGEGKYIGQWYGPNTVAQVLRKLAVFDQWSSIAVHIAMDNTVVVDEIRRLCRAGSGESSDAGALSNGYTGDSDPSCAQWKPLVLLIPLRLGLSEINEAYIETLKHCFMVPQSLGVIGGRPNSAHYFIGYVGDELIYLDPHTTQLSVEPSDCSFIEDESFHCQHPPCRMHVSEIDPSIAVGFFCSSQEDFEDWCQHIKKLSLSGGALPMFEVVDQLPLHLSNPDVLNLTPDSSDADRLDRFFDSEDEEFEILSL |
| Enzyme Length | 384 |
| Uniprot Accession Number | Q640G7 |
| Absorption | |
| Active Site | ACT_SITE 74; /note=Nucleophile; /evidence=ECO:0000250|UniProtKB:Q9Y4P1; ACT_SITE 269; /evidence=ECO:0000250|UniProtKB:Q9Y4P1; ACT_SITE 271; /evidence=ECO:0000250|UniProtKB:Q9Y4P1 |
| Activity Regulation | |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | CATALYTIC ACTIVITY: Reaction=[protein]-C-terminal L-amino acid-glycyl-phosphatidylethanolamide + H2O = [protein]-C-terminal L-amino acid-glycine + a 1,2-diacyl-sn-glycero-3-phosphoethanolamine; Xref=Rhea:RHEA:67548, Rhea:RHEA-COMP:17323, Rhea:RHEA-COMP:17324, ChEBI:CHEBI:15377, ChEBI:CHEBI:64612, ChEBI:CHEBI:172940, ChEBI:CHEBI:172941; Evidence={ECO:0000250|UniProtKB:Q9Y4P1};PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:67549; Evidence={ECO:0000250|UniProtKB:Q9Y4P1}; CATALYTIC ACTIVITY: Reaction=[protein]-C-terminal L-amino acid-glycyl-phosphatidylserine + H2O = [protein]-C-terminal L-amino acid-glycine + a 1,2-diacyl-sn-glycero-3-phospho-L-serine; Xref=Rhea:RHEA:67576, Rhea:RHEA-COMP:17324, Rhea:RHEA-COMP:17326, ChEBI:CHEBI:15377, ChEBI:CHEBI:57262, ChEBI:CHEBI:172940, ChEBI:CHEBI:172942; Evidence={ECO:0000250|UniProtKB:Q9Y4P1};PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:67577; Evidence={ECO:0000250|UniProtKB:Q9Y4P1}; |
| DNA Binding | |
| EC Number | 3.4.22.- |
| Enzyme Function | FUNCTION: 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 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. In addition to the protease activity, also mediates delipidation of ATG8 family proteins. Catalyzes delipidation of PE-conjugated forms of ATG8 proteins during macroautophagy. Also involved in non-canonical autophagy, a parallel pathway involving conjugation of ATG8 proteins to single membranes at endolysosomal compartments, by catalyzing delipidation of ATG8 proteins conjugated to phosphatidylserine (PS). {ECO:0000250|UniProtKB:Q9Y4P1}. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | |
| Features | Active site (3); Chain (1); Motif (1) |
| Keywords | Autophagy;Cytoplasm;Cytoplasmic vesicle;Endoplasmic reticulum;Hydrolase;Mitochondrion;Protease;Protein transport;Thiol protease;Transport;Ubl conjugation pathway |
| Interact With | |
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:Q9Y4P1}. Cytoplasm, cytosol {ECO:0000250|UniProtKB:Q9Y4P1}. Cytoplasmic vesicle, autophagosome {ECO:0000250|UniProtKB:Q9Y4P1}. Endoplasmic reticulum {ECO:0000250|UniProtKB:Q9Y4P1}. Mitochondrion {ECO:0000250|UniProtKB:Q9Y4P1}. Note=Mainly localizes to the cytoplasm, including cytosol. {ECO:0000250|UniProtKB:Q9Y4P1}. |
| Modified Residue | |
| Post Translational Modification | |
| Signal Peptide | |
| Structure 3D | |
| Cross Reference PDB | - |
| Mapped Pubmed ID | - |
| Motif | MOTIF 379..382; /note=LIR; /evidence=ECO:0000250|UniProtKB:Q9Y4P1 |
| Gene Encoded By | |
| Mass | 43,158 |
| Kinetics | |
| Metal Binding | |
| Rhea ID | RHEA:67548; RHEA:67549; RHEA:67576; RHEA:67577 |
| Cross Reference Brenda |