Question

Cadherins are transmembrane receptors that have 3 structural domains, each with distinct functions. Describe the structure and function of each of these receptor domains.

Answer 1

Cadherins are a type of cell adhesion molecule that is important in the formation of adherens junctions to bind cells with each other. cadherins are a class of type 1 transmembrane proteins. they are dependent on calcium ions to function, hence their name. cell cell adhesion is mediated by extracellular cadherin domains, whwe as the intercellular cytoplasmic tail associated with a large number of adaptor and signaling proteins, collectively reffered to as the cadharins adhesome.

Cadherins are a group of transdermal protien that serve as the major adhesion molecule located within adherens junctions. they can regulate cell cell adhesion through their extraceluar domain connect to the actin cytoskeleton by binding to catenins.

Caderins are synthesized as polypeptides and undergo many post translational modifications to become the protiens which mediate cell cell adhesion and recognition. these polypeptides are approximately 720 - 750 amino acids long. each cadherin has a small cytoplasmic comonent, a transmembrabe component, and the remaining bulk of the protein is extra cellular ( out side the cell). the transmembrane components consists of single chain glycoprotien repeats. beacause cadharins are ca+2 dependent, they have five tandem extracellular domain repeats that act as the binding site for ca+2 ions their extracellular domain repeats that act as the binding site ca+2 ions. their extracellular domian interacts in two separates trans dimer conformation strands swap dimer( S- dimer) and X -dimers. to date, over 100types of cadherins in humans have been identified  and sequenced.\

The functionally of cadherins relies upon the formstion of two identical subunits, know as homodimers. the homodimerss cadherins create cell cell adhesion with cadgerins oresent in the membrane of other cells through changing conformation from cis dimer to trans dimer . once the cell cell adhesion between cadherins present in the cell membrane of two different cells then be made when protein complexes, usually composed of alfa, beta, and gamma catenins, bind to the actin cytosjeleton portion of the cadherins.