LMAN1
Encyclopedia
Protein ERGIC-53 also known as ER-Golgi intermediate compartment 53 kDa protein or lectin mannose-binding 1 is a protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the LMAN1 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

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Function

ERGIC-53 is a type I integral membrane protein
Membrane protein
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle. More than half of all proteins interact with membranes.-Function:...

 localized in the intermediate region between the endoplasmic reticulum
Endoplasmic reticulum
The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...

 and the Golgi
Golgi
Golgi may refer to:*Camillo Golgi , Italian physician and scientist after which the following terms are named:**Golgi apparatus , an organelle in the eukaryotic cell...

, presumably recycling between the two compartments. Also named LMAN1, the protein is a mannose
Mannose
Mannose is a sugar monomer of the aldohexose series of carbohydrates. Mannose is a C-2 epimer of glucose. It is not part of human metabolism, but is a component of microbial cell walls, and is therefore a target of the immune system and also of antibiotics....

-specific lectin
Lectin
Lectins are sugar-binding proteins that are highly specific for their sugar moieties. They play a role in biological recognition phenomena involving cells and proteins. For example, some viruses use lectins to attach themselves to the cells of the host organism during infection...

 and is a member of a novel family of plant lectin homologs in the secretory pathway
Secretory pathway
The secretory pathway is a series of steps a cell uses to move proteins out of the cell; a process known as secretion. The path of a protein destined for secretion has its origins in the rough endoplasmic reticulum, a membrane-bound compartment in the cell...

 of animal cells. Mutations in the gene are associated with a coagulation
Coagulation
Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...

 defect. Using positional cloning, the gene was identified as the disease gene leading to combined deficiency of factor V-factor VIII, a rare, autosomal recessive disorder in which both coagulation factors V and VIII are diminished. MCFD2
MCFD2
Multiple coagulation factor deficiency protein 2 is a protein that in humans is encoded by the MCFD2 gene. Mutations in MCFD2 cause the combined deficiency of factor V and factor VIII , a recessive bleeding disorder. MCFD2 and ERGIC-53 form a protein complex and serve as a cargo receptor to...

 is the second gene that leads to combined deficiency of factor V-factor VIII. ERGIC-53 and MCFD2 form a protein complex and serve as a cargo receptor to transport FV and FVIII from the ER to the Golgi body.

Clinical Signficance

LMAN1 mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

al inactivation is a frequent and early event potentially contributing to colorectal tumorigenesis
Colorectal cancer
Colorectal cancer, commonly known as bowel cancer, is a cancer caused by uncontrolled cell growth , in the colon, rectum, or vermiform appendix. Colorectal cancer is clinically distinct from anal cancer, which affects the anus....

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Further reading

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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