Mannose 6-phosphate receptor
The mannose 6-phosphate receptors (MPRs) are transmembrane glycoproteins that target enzymes to lysosomes in vertebrates.
Cation-independent mannose-6-phosphate receptor repeat | |||||||||
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Identifiers | |||||||||
Symbol | CIMR | ||||||||
Pfam | PF00878 | ||||||||
InterPro | IPR000479 | ||||||||
SCOP2 | 1e6f / SCOPe / SUPFAM | ||||||||
Membranome | 30 | ||||||||
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Cation-dependent mannose-6-phosphate receptor | |||||||
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Identifiers | |||||||
Symbol | M6PR | ||||||
NCBI gene | 4074 | ||||||
HGNC | 6752 | ||||||
OMIM | 154540 | ||||||
RefSeq | NM_002355 | ||||||
UniProt | P20645 | ||||||
Other data | |||||||
Locus | Chr. 12 p13 | ||||||
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Cation-independent mannose-6 phosphate receptor | |||||||
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Identifiers | |||||||
Symbol | IGF2R | ||||||
NCBI gene | 3482 | ||||||
HGNC | 5467 | ||||||
OMIM | 147280 | ||||||
RefSeq | NM_000876 | ||||||
UniProt | P11717 | ||||||
Other data | |||||||
Locus | Chr. 6 q25q27 | ||||||
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Mannose 6-phosphate receptors bind newly synthesized lysosomal hydrolases in the trans-Golgi network (TGN) and deliver them to pre-lysosomal compartments. There are two different MPRs, one of ~300kDa and a smaller, dimeric receptor of ~46kDa. The larger receptor is known as the cation-independent mannose 6-phosphate receptor (CI-MPR), while the smaller receptor (CD-MPR) requires divalent cations to efficiently recognize lysosomal hydrolases. While divalent cations are not essential for ligand binding by the human CD-MPR, the nomenclature has been retained.
Both of these receptors bind terminal mannose 6-phosphate with similar affinity (CI-MPR = 7 μM, CD-MPR = 8 μM) and have similar signals in their cytoplasmic domains for intracellular trafficking.