MitoProteome Database

New search | Record Overview | Ontology/Pathway Information | Domain Information | UniProt Annotations | Related Proteins

MT000872

UniProt Annotations

Entry Information

Gene Name	autophagy related 4B, cysteine peptidase
Protein Entry	ATG4B_HUMAN
UniProt ID	Q9Y4P1
Species	Human

Comments

Comment type	Description
Alternative Products	Event=Alternative splicing; Named isoforms=5; Name=1; IsoId=Q9Y4P1-1; Sequence=Displayed; Name=2; IsoId=Q9Y4P1-2; Sequence=VSP_013029, VSP_013034; Note=No experimental confirmation available.; Name=3; IsoId=Q9Y4P1-3; Sequence=VSP_013028, VSP_013031, VSP_013032; Note=No experimental confirmation available.; Name=4; IsoId=Q9Y4P1-4; Sequence=VSP_013028, VSP_013033; Name=6; IsoId=Q9Y4P1-6; Sequence=VSP_013034; Note=No experimental confirmation available.;
Biophysicochemical Properties	Kinetic parameters: KM=5.1 uM for MAP1LC3B {ECO:0000269\|PubMed:21177865, ECO:0000269\|PubMed:22302004}; KM=5.8 uM for GABARAP {ECO:0000269\|PubMed:21177865, ECO:0000269\|PubMed:22302004}; KM=4.4 uM for GABARAPL1 {ECO:0000269\|PubMed:21177865, ECO:0000269\|PubMed:22302004}; KM=6.1 uM for GABARAPL2 {ECO:0000269\|PubMed:21177865, ECO:0000269\|PubMed:22302004};
Enzyme Regulation	Inhibited by N-ethylmaleimide. Redox-regulated during autophagy since reducing conditions activate ATG4A whereas an oxidizing environment such as the presence of H(2)O(2) inhibits its activity. {ECO:0000269\|PubMed:17347651}.
Function	Cysteine protease required for the cytoplasm to vacuole transport (Cvt) and autophagy. Cleaves the C-terminal amino acid of ATG8 family proteins MAP1LC3, 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. Has also an activity of delipidating enzyme for the PE-conjugated forms. {ECO:0000269\|PubMed:15169837, ECO:0000269\|PubMed:15187094, ECO:0000269\|PubMed:17347651, ECO:0000269\|PubMed:19322194, ECO:0000269\|PubMed:21177865, ECO:0000269\|PubMed:22302004}.
Interaction	O95166:GABARAP; NbExp=8; IntAct=EBI-712014, EBI-712001; Q9H0R8:GABARAPL1; NbExp=7; IntAct=EBI-712014, EBI-746969; P60520:GABARAPL2; NbExp=7; IntAct=EBI-712014, EBI-720116; Q9GZQ8:MAP1LC3B; NbExp=11; IntAct=EBI-712014, EBI-373144;
Sequence Caution	Sequence=BAA76787.2; Type=Erroneous initiation; Note=Translation N-terminally shortened.; Evidence={ECO:0000305}; Sequence=BAC86110.1; Type=Erroneous initiation; Note=Translation N-terminally shortened.; Evidence={ECO:0000305};
Similarity	Belongs to the peptidase C54 family. {ECO:0000305}.
Subcellular Location	Cytoplasm {ECO:0000250}.
Tissue Specificity	Mainly expressed in the skeletal muscle, followed by brain, heart, liver and pancreas. {ECO:0000269\|PubMed:12446702, ECO:0000269\|PubMed:15169837}.