UniProt functional annotation for Q5XPI4



	UniProt functional annotation for Q5XPI4

UniProt code: Q5XPI4.

Organism: Homo sapiens (Human).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.

Function: Catalytic subunit of the KPC complex that acts as E3 ubiquitin-protein ligase. Promotes the ubiquitination and proteasome- mediated degradation of CDKN1B which is the cyclin-dependent kinase inhibitor at the G0-G1 transition of the cell cycle (PubMed:15531880, PubMed:16227581). Functions also as an inhibitor of innate antiviral signaling mediated by DDX58 and IFIH1 independently of its E3 ligase activity (PubMed:27312109). Interacts with the N-terminal CARD domains of DDX58 and IFIH1 and competes with the downstream adapter MAVS (PubMed:27312109). {ECO:0000269|PubMed:15531880, ECO:0000269|PubMed:16227581, ECO:0000269|PubMed:27312109}.

Catalytic activity: Reaction=S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L- cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine.; EC=2.3.2.27;

Pathway: Protein modification; protein ubiquitination.

Subunit: Component of the KPC complex composed of RNF123/KPC1 and UBAC1/KPC2. Interacts with UBAC1 and CDKN1B via its N-terminal domain. Interacts with DDX58 (via N-terminus) and IFIH1 (via N-terminus). {ECO:0000269|PubMed:15531880, ECO:0000269|PubMed:16227581, ECO:0000269|PubMed:27312109}.

Subcellular location: Cytoplasm {ECO:0000269|PubMed:15531880, ECO:0000269|PubMed:27312109}.

Ptm: Ubiquitinated, leading to its degradation. Deubiquitinated by USP19, thereby stimulating CDKN1B ubiquitin-dependent degradation. {ECO:0000250|UniProtKB:D3ZXK7}.

Sequence caution: Sequence=BAB14139.1; Type=Erroneous initiation; Evidence={ECO:0000305}; Sequence=BAB15607.1; Type=Erroneous initiation; Evidence={ECO:0000305};

Annotations taken from UniProtKB at the EBI.


Organism:		Homo sapiens (Human).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.



Function:		Catalytic subunit of the KPC complex that acts as E3 ubiquitin-protein ligase. Promotes the ubiquitination and proteasome- mediated degradation of CDKN1B which is the cyclin-dependent kinase inhibitor at the G0-G1 transition of the cell cycle (PubMed:15531880, PubMed:16227581). Functions also as an inhibitor of innate antiviral signaling mediated by DDX58 and IFIH1 independently of its E3 ligase activity (PubMed:27312109). Interacts with the N-terminal CARD domains of DDX58 and IFIH1 and competes with the downstream adapter MAVS (PubMed:27312109). {ECO:0000269\|PubMed:15531880, ECO:0000269\|PubMed:16227581, ECO:0000269\|PubMed:27312109}.


Catalytic activity:		Reaction=S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L- cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine.; EC=2.3.2.27;
Pathway:		Protein modification; protein ubiquitination.
Subunit:		Component of the KPC complex composed of RNF123/KPC1 and UBAC1/KPC2. Interacts with UBAC1 and CDKN1B via its N-terminal domain. Interacts with DDX58 (via N-terminus) and IFIH1 (via N-terminus). {ECO:0000269\|PubMed:15531880, ECO:0000269\|PubMed:16227581, ECO:0000269\|PubMed:27312109}.
Subcellular location:		Cytoplasm {ECO:0000269\|PubMed:15531880, ECO:0000269\|PubMed:27312109}.
Ptm:		Ubiquitinated, leading to its degradation. Deubiquitinated by USP19, thereby stimulating CDKN1B ubiquitin-dependent degradation. {ECO:0000250\|UniProtKB:D3ZXK7}.
Sequence caution:		Sequence=BAB14139.1; Type=Erroneous initiation; Evidence={ECO:0000305}; Sequence=BAB15607.1; Type=Erroneous initiation; Evidence={ECO:0000305};