MUL1

MUL1 (Mitochondrial E3 Ubiquitin Protein Ligase 1) is a Protein Coding gene. Among its related pathways are Metabolism of proteins and Deubiquitination. Gene Ontology (GO) annotations related to this gene include identical protein binding and ubiquitin-protein transferase activity.

Full Name

MITOCHONDRIAL E3 UBIQUITIN PROTEIN LIGASE 1

Function

Exhibits weak E3 ubiquitin-protein ligase activity (PubMed:18591963, PubMed:19407830, PubMed:22410793).

E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfer the ubiquitin to targeted substrates (PubMed:18591963, PubMed:19407830, PubMed:22410793).

Can ubiquitinate AKT1 preferentially at 'Lys-284' involving 'Lys-48'-linked polyubiquitination and seems to be involved in regulation of Akt signaling by targeting phosphorylated Akt to proteosomal degradation (PubMed:22410793).

Mediates polyubiquitination of cytoplasmic TP53 at 'Lys-24' which targets TP53 for proteasomal degradation, thus reducing TP53 levels in the cytoplasm and mitochondrion (PubMed:21597459).

Proposed to preferentially act as a SUMO E3 ligase at physiological concentrations (PubMed:19407830).

Plays a role in the control of mitochondrial morphology by promoting mitochondrial fragmentation, and influences mitochondrial localization (PubMed:19407830, PubMed:18207745, PubMed:18213395).

Likely to promote mitochondrial fission through negatively regulating the mitochondrial fusion proteins MFN1 and MFN2, acting in a pathway that is parallel to the PRKN/PINK1 regulatory pathway (PubMed:24898855).

May also be involved in the sumoylation of the membrane fission protein DNM1L (PubMed:18207745, PubMed:19407830).

Inhibits cell growth (PubMed:18591963, PubMed:22410793).

When overexpressed, activates JNK through MAP3K7/TAK1 and induces caspase-dependent apoptosis (PubMed:23399697).

Involved in the modulation of innate immune defense against viruses by inhibiting DDX58-dependent antiviral response (PubMed:23399697).

Can mediate DDX58 sumoylation and disrupt its polyubiquitination (PubMed:23399697).

Biological Process

Activation of cysteine-type endopeptidase activity involved in apoptotic process Source: UniProtKB
Apoptotic process Source: UniProtKB-KW
Cellular response to exogenous dsRNA Source: UniProtKB
Mitochondrial fission Source: UniProtKB
Mitochondrion localization Source: UniProtKB
Negative regulation of cell growth Source: UniProtKB
Negative regulation of chemokine (C-C motif) ligand 5 production Source: UniProtKB
Negative regulation of defense response to virus by host Source: UniProtKB
Negative regulation of innate immune response Source: UniProtKB
Negative regulation of mitochondrial fusion Source: UniProtKB
Negative regulation of protein kinase B signaling Source: UniProtKB
Negative regulation of type I interferon-mediated signaling pathway Source: UniProtKB
Positive regulation of autophagy of mitochondrion in response to mitochondrial depolarization Source: Ensembl
Positive regulation of dendrite extension Source: Ensembl
Positive regulation of I-kappaB kinase/NF-kappaB signaling Source: UniProtKB
Positive regulation of mitochondrial fission Source: UniProtKB
Positive regulation of protein sumoylation Source: UniProtKB
Protein destabilization Source: ParkinsonsUK-UCL
Protein polyubiquitination Source: UniProtKB
Protein stabilization Source: UniProtKB
Protein ubiquitination Source: UniProtKB
Regulation of mitochondrial membrane potential Source: Ensembl
Regulation of mitochondrial outer membrane permeabilization involved in apoptotic signaling pathway Source: UniProtKB
Regulation of mitochondrion organization Source: ParkinsonsUK-UCL

Cellular Location

Mitochondrion
Mitochondrion outer membrane
Peroxisome
Note: Transported in mitochondrion-derived vesicles from the mitochondrion to the peroxisome.

Topology

Cytoplasmic: 1-8
Helical: 9-29
Mitochondrial intermembrane: 30-238
Helical: 239-259
Cytoplasmic: 260-352

PTM

Ubiquitinated by PRKN during mitophagy, leading to its degradation and enhancement of mitophagy. Deubiquitinated by USP30.