Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara
Electronic Gene Ontology annotations created by ARBA machine learning models
Crystal structure and immunoglobulin G binding properties of the human major histocompatibility complex-related Fc receptor(,).
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The 2.7 A crystal structure of human FcRn shows that although it is structurally related to class I MHC proteins, its alpha-1/alpha-2 groove is closed and lacks a functional peptide-binding groove, while binding human IgG with a 2:1 receptor:ligand stoichiometry.
"FcRn is related to class I MHC proteins but lacks a functional peptide binding groove."
Structural insights into neonatal Fc receptor-based recycling mechanisms.
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Co-crystal structures of human FcRn bound concurrently to human serum albumin (HSA) and engineered IgG Fc show non-overlapping ligand interfaces, with HSA domain III making extensive contacts and FcRn His161 (mature numbering; His184 precursor) mediating pH-dependent albumin recycling.
"We report the three-dimensional structure of human neonatal Fc receptor (FcRn) bound concurrently to its two known ligands. More particularly, we solved the crystal structure of the complex between human FcRn, wild-type human serum albumin (HSA), and a human Fc engineered for improved pharmacokinetics properties (Fc-YTE)."
Hepatic FcRn regulates albumin homeostasis and susceptibility to liver injury.
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FcRn maintains circulating serum albumin homeostasis by mediating basal recycling and bidirectional transcytosis of albumin in polarized cells and directing hepatic albumin into the circulation rather than bile.
"In vitro models with polarized cells illustrate that FcRn mediates basal recycling and bidirectional transcytosis of albumin and uniquely determines the physiologic release of newly synthesized albumin into the basal milieu."
Human Neonatal Fc Receptor Is the Cellular Uncoating Receptor for Enterovirus B.
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Human FcRn is an MHC class I-like heterodimer composed of the heavy alpha chain (FCGRT) and beta-2-microglobulin (B2M) that localizes to the cell surface and endosome membrane.
"FcRn is an MHC class I-like protein consisting of a heavy α chain encoded by the FCGRT gene, and a light β2-microglubulin (β2 m) chain encoded by the B2M gene."
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Confocal microscopy shows that FcRn is predominantly localized to intracellular compartments corresponding to the endosome membrane as well as the cell surface.
"Consistently, CD55 was mainly localized on the cell surface, whereas FcRn displayed substantial expression within the cytoplasm, presumably on the endosome membrane"
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During Enterovirus B infection, the FCGRT subunit of FcRn binds the viral capsid canyon and induces pocket-factor release and capsid uncoating at acidic endosomal pH (pH 5.5).
"Here, we found that human neonatal Fc receptor (FcRn) is the uncoating receptor for major EV-B. FcRn binds to the virus particles in the "canyon" through its FCGRT subunit."
A reference map of the human binary protein interactome.
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High-throughput yeast two-hybrid screening (HuRI) mapped binary human protein-protein interactions across the human ORFeome.
"Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'."
A major histocompatibility complex class I-like Fc receptor cloned from human placenta: possible role in transfer of immunoglobulin G from mother to fetus.
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Human FCGRT (hFcRn) cloned from placenta encodes an MHC class I-like heavy chain that binds IgG preferentially at acidic pH to mediate transplacental maternal-fetal IgG transport.
"Like rat and mouse FcRn, hFcRn binds IgG preferentially at low pH, which may imply that IgG binds hFcRn in an acidic intracellular compartment during transport across the placenta."
UniProtKB record for human FCGRT (P55899)
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FCGRT is a single-pass type I membrane protein localized to the plasma membrane and endosome membrane that forms a heterodimer with beta-2-microglobulin and mediates pH-dependent transcytosis and recycling of monomeric IgG and serum albumin.
"SUBCELLULAR LOCATION: Cell membrane {ECO:0000250|UniProtKB:P13599}; Single-pass type I membrane protein {ECO:0000255}. Endosome membrane {ECO:0000269|PubMed:31104841}."