About JAM / Junctional Adhesion Molecule:
JAM (junctional adhesion molecule) is a protein that belongs to the immunoglobulin superfamily and is found in several tissues, including leukocytes, platelets, epithelial and endothelial cells. They have been shown to control signal complex assembly on both their cytoplasmic and extracellular domains by interacting with scaffolding containing a PDZ domain and adjacent cell receptors.
JAMs bind to neighbouring cells by interacting with the integrins LFA-1 and Mac-1, which are found in leukocytes 2 and 41, respectively. JAMs have various effects on leukocyte-endothelial cell interactions, which are mostly mediated by the integrins mentioned earlier.
Junctional Adhesion Molecule Structure
JAMs are usually 40 kDa in size. JAM is made up of an immunoglobulin-like V-set domain followed by a second immunoglobulin domain connected by a short linker sequence, according to crystallographic studies done with recombinant extracellular mouse JAMs (rsJAM) and human JAMs (hJAM). Both domains are connected by the linker, which forms extensive hydrogen bonds.
JAMs have different functions within the cells;
●Cell motility - JAMs are important regulators of cell movement in various cell types, including epithelial, endothelial, leukocyte, and germ cells.
●Cell polarity - Via their interactions with cell polarity proteins, JAM-1 and JAM-3 play important roles in controlling cell polarity. To affect cell polarity, JAM-1, JAM-2, and JAM-3 all associate with PAR-3. PAR-3 is an important component of a cell's polarity-regulating complex, and it controls polarity in a variety of cell types in various species.
●Cell proliferation - To preserve adult tissue homeostasis, aged cells must be replaced with new cells at varying frequencies, depending on the organ.