scholarly journals A human mannose-binding protein is an acute-phase reactant that shares sequence homology with other vertebrate lectins.

1988 ◽  
Vol 167 (3) ◽  
pp. 1034-1046 ◽  
Author(s):  
R A Ezekowitz ◽  
L E Day ◽  
G A Herman
Keyword(s):  
Acute Phase ◽  
Disulfide Bonds ◽  
Signal Sequence ◽  
Binding Protein ◽  
Protein A ◽  
Coelomic Fluid ◽  
Carbohydrate Binding ◽  
Cdna Clones ◽  
Mannose Binding Protein ◽  
Mannose Binding

Mannose-binding proteins have been isolated from the liver of rats and humans and subsequently been found in the serum of rats, rabbits, and humans. We report the isolation of cDNA clones isolated from a human liver cDNA library that encodes a human mannose-binding protein. The primary structure has three domains: (a) an NH2-terminal cysteine-rich segment of 19 amino acids which appears to be involved in the formation of interchain disulfide bonds that would stabilize multimeric forms of the protein; (b) a collagen-like region consisting of 19 repeats of the sequence Gly-x-y; and (c) a COOH-terminal putative carbohydrate-binding domain consisting of 148 residues. This human mannose-binding protein bears 51% overall homology (allowing three gaps) with a rat mannose-binding protein C and 48% homology (allowing seven gaps) with a rat mannose-binding protein A. Like these homologous rat proteins, the human mannose-binding protein COOH-terminal sequences are homologous to the carbohydrate recognition portion of several other lectin-like proteins including mammalian hepatic receptors, an insect-soluble hemolymph, and a sea urchin lectin found in coelomic fluid. The apoproteins of dog and human surfactant and the human lymphocyte IgE Ec receptor have not been shown to have lectin-like properties, yet by homology are members of this family of lectin-like proteins. The human mannose-binding protein is preceded by a typical hydrophobic signal sequence and its hepatic secretion is induced as part of the acute-phase response consistent with its probable role in host defense.

Introduction of Mannose Binding Protein-Type Phosphatidylinositol Recognition into Pulmonary Surfactant Protein A†

Biochemistry ◽  
1999 ◽  
Vol 38 (22) ◽  
pp. 7321-7331 ◽  
Author(s):  
Hirofumi Chiba ◽  
Hitomi Sano ◽  
Masaki Saitoh ◽  
Hitoshi Sohma ◽  
Dennis R. Voelker ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
Binding Protein ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Pulmonary Surfactant Protein

scholarly journals Rat Mannose-Binding Protein A Binds CD14

2001 ◽  
Vol 69 (3) ◽  
pp. 1587-1592 ◽  
Author(s):  
Hirofumi Chiba ◽  
Hitomi Sano ◽  
Daisuke Iwaki ◽  
Seiji Murakami ◽  
Hiroaki Mitsuzawa ◽  
...  
Keyword(s):  
Lipid A ◽  
Binding Protein ◽  
Protein A ◽  
Cellular Responses ◽  
Dependent Manner ◽  
Soluble Cd14 ◽  
Concentration Dependent Manner ◽  
E Coli ◽  
Mannose Binding Protein ◽  
Mannose Binding

ABSTRACT Lipopolysaccharide (LPS) has been known to induce inflammation by interacting with CD14, which serves as a receptor for LPS. Mannose-binding protein (MBP) belongs to the collectin subgroup of the C-type lectin superfamily, along with surfactant proteins SP-A and SP-D. We have recently demonstrated that SP-A modulates LPS-induced cellular responses by interaction with CD14 (H. Sano, H. Sohma, T. Muta, S. Nomura, D. R. Voelker, and Y. Kuroki, J. Immunol. 163:387–395, 2000) and that SP-D also interacts with CD14 (H. Sano, H. Chiba, D. Iwaki, H. Sohma, D. R. Voelker, and Y. Kuroki, J. Biol. Chem. 275:22442–22451, 2000). In this study, we examined whether MBP, a collectin highly homologous to SP-A and SP-D, could bind CD14. Recombinant rat MBP-A bound recombinant human soluble CD14 in a concentration-dependent manner. Its binding was not inhibited in the presence of excess mannose or EDTA. MBP-A bound deglycosylated CD14 treated with N-glycosidase F, neuraminidase, and O-glycosidase, indicating that MBP-A interacts with the peptide portion of CD14. Since LPS was also a ligand for the collectins, we compared the characteristics of binding of MBP-A to LPS with those of binding to CD14. MBP-A bound to lipid A fromSalmonella enterica serovar Minnesota and rough LPS (S. enterica serovar Minnesota Re595 and Escherichia coli J5, Rc), but not to smooth LPS (E. coli O26:B6 and O111:B4). Unlike CD14 binding, EDTA and excess mannose attenuated the binding of MBP-A to rough LPS. From these results, we conclude that CD14 is a novel ligand for MBP-A and that MBP-A utilizes a different mechanism for CD14 recognition from that for LPS.

scholarly journals Structure and evolutionary origin of the gene encoding a human serum mannose-binding protein

1989 ◽  
Vol 262 (3) ◽  
pp. 763-771 ◽  
Author(s):  
M E Taylor ◽  
P M Brickell ◽  
R K Craig ◽  
J A Summerfield
Keyword(s):  
Human Serum ◽  
Cdna Clone ◽  
Binding Protein ◽  
Neck Region ◽  
Homologous Gene ◽  
Carbohydrate Binding ◽  
Gene Encoding ◽  
Consensus Sequences ◽  
Mannose Binding Protein ◽  
Mannose Binding

The N-terminal sequence of the major human serum mannose-binding protein (MBP1) was shown to be identical at all positions determined with the amino acid sequence predicted from a cDNA clone of a human liver MBP mRNA. An oligonucleotide corresponding to part of the sequence of this cDNA clone was used to isolate a cosmid genomic clone containing a homologous gene. The intron/exon structure of this gene was found to closely resemble that of the gene encoding a rat liver MBP (MBP A). The nucleotide sequence of the exons differed in several places from that of the human cDNA clone published by Ezekowitz, Day & Herman [(1988) J. Exp. Med. 167, 1034-1046]. The MBP molecule comprises a signal peptide, a cysteine-rich domain, a collagen-like domain, a ‘neck’ region and a carbohydrate-binding domain. Each domain is encoded by a separate exon. This genomic organization lends support to the hypothesis that the gene arose during evolution by a process of exon shuffling. Several consensus sequences that may be involved in controlling the expression of human serum MBP have been identified in the promoter region of the gene. The consensus sequences are consistent with the suggestion that this mammalian serum lectin is regulated as an acute-phase protein synthesized by the liver.

scholarly journals Trypanosoma cruzi amastigote adhesion to macrophages is facilitated by the mannose receptor.

1995 ◽  
Vol 182 (5) ◽  
pp. 1243-1258 ◽  
Author(s):  
S Kahn ◽  
M Wleklinski ◽  
A Aruffo ◽  
A Farr ◽  
D Coder ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mammalian Cells ◽  
Binding Protein ◽  
Mannose Receptor ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
Carbohydrate Binding ◽  
Mouse Tissues ◽  
Mannose Binding Protein ◽  
Mannose Binding

Trypanosoma cruzi is an obligate intracellular protozoan parasite. The mammalian stage of the parasite life cycle describes amastigotes as an intracellular form that replicates, and trypomastigotes as an extracellular form that disseminates and invades cells. Recent studies, however, have demonstrated that amastigotes circulate in the blood of infected mammals and can invade mammalian cells. In this report, a T. cruzi surface glycoprotein gene, SA85-1.1, was expressed as an immunoglobulin chimera, and this recombinant globulin was used to screen normal mouse tissues for adhesive interactions. This approach identified a subset of macrophages in the skin and peripheral lymph node that bind the T. cruzi surface glycoproteins through the mannose receptor. To further examine the T. cruzi mannose receptor carbohydrate ligands, the interaction between T. cruzi and the mannose-binding protein, a mammalian lectin with similar carbohydrate binding specificities as the mannose receptor, was examined. These studies demonstrated that the mannose-binding protein recognized amastigotes, but not trypomastigotes or epimastigotes, and suggested that amastigotes would also be recognized by the mannose receptor. Therefore, amastigote adhesion to macrophages was investigated, and these experiments demonstrated that the mannose receptor contributes to amastigote adhesion. The data identify the first mammalian lectins that bind to T. cruzi, and are involved in T. cruzi invasion of mammalian cells. The data suggest that amastigotes and trypomastigotes may have developed different mechanisms to adhere to and invade host cells. In addition, it has been established that IFN-gamma-activated macrophages express low levels of the mannose receptor and are trypanocidal; this suggests that the interaction between amastigotes and the mannose receptor enables amastigotes to increase their adherence with a population of macrophages that are nontrypanocidal and permissive for their intracellular replication.

The human ortholog of rhesus mannose-binding protein-A gene is an expressed pseudogene that localizes to Chromosome 10

1998 ◽  
Vol 9 (3) ◽  
pp. 246-249 ◽  
Author(s):  
Ning Guo ◽  
Tirsit Mogues ◽  
Stanislawa Weremowicz ◽  
Cynthia C. Morton ◽  
Kedarnath N. Sastry
Keyword(s):  
Binding Protein ◽  
Protein A ◽  
Chromosome 10 ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Human Ortholog

scholarly journals The human mannose-binding protein functions as an opsonin.

1989 ◽  
Vol 169 (5) ◽  
pp. 1733-1745 ◽  
Author(s):  
M Kuhlman ◽  
K Joiner ◽  
R A Ezekowitz
Keyword(s):  
Host Defense ◽  
Binding Protein ◽  
Alpha Helix ◽  
Carbohydrate Binding ◽  
Wild Type ◽  
Binding Region ◽  
First Line ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Protein Functions

The human mannose-binding protein (MBP) is a multimeric serum protein that is divided into three domains: a cysteine-rich NH2-terminal domain that stabilizes the alpha-helix of the second collagen-like domain, and a third COOH-terminal carbohydrate binding region. The function of MBP is unknown, although a role in host defense is suggested by its ability to bind yeast mannans. In this report we show that native and recombinant human MBP can serve in an opsonic role in serum and thereby enhance clearance of mannose rich pathogens by phagocytes. MBP binds to wild-type virulent Salmonella montevideo that express a mannose-rich O-polysaccharide. Interaction of MBP with these organisms results in attachment, uptake, and killing of the opsonized bacteria by phagocytes. These results demonstrate that MBP plays a role in first line host defense against certain pathogenic organisms.

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