Junctional adhesion molecule C is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''JAM3''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Gene
This gene is located on the long arm of
chromosome 11
Chromosome 11 is one of the 23 pairs of chromosomes in humans. Humans normally have two copies of this chromosome. Chromosome 11 spans about 135 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the tota ...
(11q25) on the Watson strand. It is 83,077 bases in length. The encoded protein is 310
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...
s long with a predicted
molecular weight
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...
of 35.02 kilodaltons.
Function
Tight junction
Tight junctions, also known as occluding junctions or ''zonulae occludentes'' (singular, ''zonula occludens''), are multiprotein Cell junction, junctional complexes between epithelial cells, sealing and preventing leakage of solutes and water. Th ...
s represent one mode of cell-to-cell adhesion in
epithelial
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...
or
endothelial
The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the res ...
cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the
paracellular
Paracellular transport refers to the transfer of substances across an epithelium by passing through the intercellular space ''between'' the cells. It is in contrast to transcellular transport, where the substances travel ''through'' the cell, pas ...
space. The protein encoded by this
immunoglobulin superfamily
The immunoglobulin superfamily (IgSF) is a large protein superfamily of cell surface and soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. Molecules are categorized as members of this superfamily ...
gene member is localized in the tight junctions between high endothelial cells. Unlike other proteins in this family, this protein is unable to adhere to
leukocyte
White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are genera ...
cell lines and only forms weak
homotypic interactions. The encoded protein is a member of the junctional adhesion molecule protein family and acts as a receptor for another member of this family.
Interactions
JAM3 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization advocating for the legal and human rights of children with intersex traits. The organization was founded in 2006 and fo ...
with
PARD3
Partitioning defective 3 homolog is a protein that in humans is encoded by the ''PARD3'' gene.
Function
PARD proteins, which were first identified in ''C. elegans'', are essential for asymmetric cell division and polarized growth, whereas CDC ...
.
Clinical significance
Loss-of-function mutations in this gene cause a rare syndrome - autosomal recessive hemorrhagic destruction of the brain, subependymal calcification and congenital cataracts.
References
Further reading
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