マクロファージマンノース受容体

貪食細胞が、直接病原体の表面を認識する細胞表面レセプターのひとつ。
N末端にR型レクチンのドメインをひとつ、Ⅱ型フィブロネクチンドメインを挟んでC型レクチンドメインを８つ連ねている。４，５番目のC型レクチンドメインがマンノース、GlcNAc、フコースに対する親和性を持つ。R型ドメインは硫酸化糖鎖に親和性をもち、下垂体糖タンパク質ホルモンの硫酸化糖鎖に結合し、ホルモンのクリアランスに関与する。
C型レクチンドメインで、多くの細菌やHIVを含むいくつかのウイルスの表面に見られるある種の糖分子に、マンノース結合レクチンとよく似た分子機構で結合する。１型の膜タンパク質であり、直接貪食細胞レセプターとして機能する。

Macrophage mannose receptor 1

Short name=MMR
Alternative name(s):
C-type lectin domain family 13 member D
C-type lectin domain family 13 member D-like
Macrophage mannose receptor 1-like protein 1
CD_antigen=CD206
:Function
Mediates the endocytosis of glycoproteins by macrophages. Binds both sulfated and non-sulfated polysaccharide chains. Acts as phagocytic receptor for bacteria, fungi and other pathogens.
Subcellular location
Endosome membrane; Single-pass type I membrane protein. Cell membrane; Single-pass type I membrane protein Ref.10.
Polymorphism
Genetic variations in MRC1 may influence susceptibility or resistance to leprosy in some populations. Particularly, Gly-396 seems to be a risk factor for leprosy when associated with Ala-399 and Phe-407.
Miscellaneous
CRDs 1-3 have at most very weak affinity for carbohydrate. CRD 4 shows the highest affinity binding and has multispecificity for a variety of monosaccharides. At least 3 CRDs (4, 5, and 7) are required for high affinity binding and endocytosis of multivalent glycoconjugates.
Sequence similarities
Contains 8 C-type lectin domains.
Contains 1 fibronectin type-II domain.
Contains 1 ricin B-type lectin domain.

C-type mannose receptor 2

Alternative name(s):
C-type lectin domain family 13 member E
Endocytic receptor 180
Macrophage mannose receptor 2
Urokinase-type plasminogen activator receptor-associated protein
Short name=UPAR-associated protein
Short name=Urokinase receptor-associated protein
CD_antigen=CD280
:Function
May play a role as endocytotic lectin receptor displaying calcium-dependent lectin activity. Internalizes glycosylated ligands from the extracellular space for release in an endosomal compartment via clathrin-mediated endocytosis. May be involved in plasminogen activation system controlling the extracellular level of PLAUR/PLAU, and thus may regulate protease activity at the cell surface. May contribute to cellular uptake, remodeling and degradation of extracellular collagen matrices. May play a role during cancer progression as well as in other chronic tissue destructive diseases acting on collagen turnover. May participate in remodeling of extracellular matrix cooperating with the matrix metalloproteinases (MMPs). Ref.2 Ref.10
Subunit structure
Interacts with C-terminal region of type I collagen/COL1A1 By similarity. Interacts directly with PLAUR/UPAR and PLAU/pro-UPA to form a tri-molecular complex. Interacts with collagen V. Ref.1
Subcellular location
Membrane; Single-pass type I membrane protein.
Tissue specificity
Ubiquitous with low expression in brain, placenta, lung, kidney, pancreas, spleen, thymus and colon. Expressed in endothelial cells, fibroblasts and macrophages. Highly expressed in fetal lung and kidney. Ref.2 Ref.7
Domain
C-type lectin domains 3 to 8 are not required for calcium-dependent binding of mannose, fucose and N-acetylglucosamine. C-type lectin domain 2 is responsible for sugar-binding in a calcium-dependent manner. Ref.9 Ref.10
Fibronectin type-II domain mediates collagen-binding. Ref.9 Ref.10
Ricin B-type lectin domain contacts with the second C-type lectin domain By similarity. Ref.9 Ref.10
Post-translational modification
N-glycosylated. Ref.2 Ref.12
Sequence similarities
Contains 8 C-type lectin domains.
Contains 1 fibronectin type-II domain.
Contains 1 ricin B-type lectin domain.