A cell junction
(or intercellular bridge
) is a type of structure that exists within the tissue
of some multicellular organisms
, such as animals
. Cell junctions consist of multiprotein complexes
that provide contact between neighboring cells
or between a cell and the extracellular matrix
. They also build up the paracellular barrier of epithelia and control the paracellular transport
. Cell junctions are especially abundant in epithelial
Cell junctions are especially important in enabling communication between neighboring cells via specialized proteins called communicating junctions. Cell junctions are also important in reducing stress placed upon cells.
In vertebrates, there are three major types of cell junction:
Invertebrates have several other types of specific junctions, for example septate junctions or the C. elegans apical junction.
In multicellular plants, the structural functions of cell junctions are instead provided for by cell walls. The analogues of communicative cell junctions in plants are called plasmodesmata.
Cells within tissues and organs must be anchored to one another and attached to components of the extracellular matrix. Cells have developed several types of junctional complexes to serve these functions, and in each case, anchoring proteins extend through the plasma membrane to link cytoskeletal proteins in one cell to cytoskeletal proteins in neighboring cells as well as to proteins in the extracellular matrix .
This page was last edited on 14 March 2018, at 01:31.
under CC BY-SA license.