Recombinant Human E3 ubiquitin-protein ligase AMFR (AMFR)

Uniprot Id

Q9UKV5

Target Species

Human

Target Name

AMFR

Target Full Name

E3 ubiquitin-protein ligase AMFR

Target Function

E3 ubiquitin-protein ligase that mediates the polyubiquitination of lysine and cysteine residues on target proteins, such as CD3D, CYP3A4, CFTR, INSIG1, SOAT2/ACAT2 and APOB for proteasomal degradation. Component of a VCP/p97-AMFR/gp78 complex that participates in the final step of endoplasmic reticulum-associated degradation (ERAD). The VCP/p97-AMFR/gp78 complex is involved in the sterol-accelerated ERAD degradation of HMGCR through binding to the HMGCR-INSIG1 complex at the ER membrane. In addition, interaction of AMFR with AUP1 facilitates interaction of AMFR with ubiquitin-conjugating enzyme UBE2G2 and ubiquitin ligase RNF139, leading to sterol-induced HMGCR ubiquitination. The ubiquitinated HMGCR is then released from the ER into the cytosol for subsequent destruction. In addition to ubiquitination on lysine residues, catalyzes ubiquitination on cysteine residues: together with INSIG1, mediates polyubiquitination of SOAT2/ACAT2 at 'Cys-277', leading to its degradation when the lipid levels are low. Catalyzes ubiquitination and subsequent degradation of INSIG1 when cells are depleted of sterols. Mediates polyubiquitination of INSIG2 at 'Cys-215' in some tissues, leading to its degradation. Also regulates ERAD through the ubiquitination of UBL4A a component of the BAG6/BAT3 complex. Also acts as a scaffold protein to assemble a complex that couples ubiquitination, retranslocation and deglycosylation. Mediates tumor invasion and metastasis as a receptor for the GPI/autocrine motility factor. In association with LMBR1L and UBAC2, negatively regulates the canonical Wnt signaling pathway in the lymphocytes by promoting the ubiquitin-mediated degradation of CTNNB1 and Wnt receptors FZD6 and LRP6.

Target Subcellular Location

Endoplasmic reticulum membrane; Multi-pass membrane protein.

Target Research Area

Cancer

Target Synonyms

AMFR; RNF45; E3 ubiquitin-protein ligase AMFR; Autocrine motility factor receptor; AMF receptor; RING finger protein 45; gp78

Target Background

This locus encodes a glycosylated transmembrane receptor. Its ligand, autocrine motility factor, is a tumor motility-stimulating protein secreted by tumor cells. The encoded receptor is also a member of the E3 ubiquitin ligase family of proteins. It catalyzes ubiquitination and endoplasmic reticulum-associated degradation of specific proteins.