The function of Ensembl gene identifier ENSG00000176407 (KCMF1, potassium channel modulatory factor 1) is as follows. E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme and then transfers it to targeted substrates, promoting their degradation by the proteasome (PubMed:15581609, PubMed:25582440, PubMed:34893540, PubMed:37891180, PubMed:38297121). Together with UBR4, component of the N-end rule pathway: ubiquitinates proteins bearing specific N-terminal residues that are destabilizing according to the N-end rule, leading to their degradation (PubMed:34893540, PubMed:37891180). Does not ubiquitinate proteins that are acetylated at the N-terminus (PubMed:37891180). Together with UBR4, part of a protein quality control pathway that catalyzes ubiquitination and degradation of proteins that have been oxidized in response to reactive oxygen species (ROS): recognizes proteins with an Arg-CysO3(H) degron at the N-terminus, and mediates assembly of heterotypic 'Lys-63'-/'Lys-27'-linked branched ubiquitin chains on oxidized proteins, leading to their degradation by autophagy (PubMed:34893540). Catalytic component of the silencing factor of the integrated stress response (SIFI) complex, a multiprotein complex that turns off the mitochondrial stress response after a specific stress event has been resolved (PubMed:38297121, PubMed:40328314, PubMed:40875847). The SIFI complex ubiquitinates and degrades (1) components of the HRI-mediated signaling of the integrated stress response, such as DELE1 and EIF2AK1/HRI, as well as (2) unimported mitochondrial precursors such as ABHD10 (PubMed:38297121, PubMed:40328314). Within the SIFI complex, UBR4 initiates ubiquitin chain that are further elongated or branched by KCMF1 (PubMed:38297121, PubMed:40328314, PubMed:40875847). {ECO:0000269|PubMed:15581609, ECO:0000269|PubMed:25582440, ECO:0000269|PubMed:34893540, ECO:0000269|PubMed:37891180, ECO:0000269|PubMed:38297121, ECO:0000269|PubMed:40328314, ECO:0000269|PubMed:40875847}.