Some cells have structures that guarantee theirjunction. These specializations work in different ways, acting, for example, in anchoring, synchronizing processes such as contraction, and exchanging information. These junctions are undone in cell division and apoptosis. Next, let's talk about one of these junctions: the desmosome.
→ desmosom
The desmosome, also called adhesion macula, is a junction that has the function of anchoring, thus allowing one cell to adhere to another. It appears as a disk-shaped structure, which is seen in a cell and adjacent to it. In these places, the membranes are flat, parallel and separated by a small space.
For this junction to occur, the participation of transmembrane proteins from the cadherin family is necessary. These proteins present in one cell project to the extracellular environment and attach themselves to proteins in another paired cell. Adjacent membranes remain held together by Ca-dependent mechanisms2+.
On the surface of the plasma membrane, facing the cytoplasm in the desmosome region, there is a plaque (
anchor plate) composed of at least 12 distinct intracellular anchoring proteins, which guarantee the association with the cytoskeleton. In epithelial cells, keratin filaments, present in the cytoplasm, are associated with anchorage plates, or forming loops in cardiac muscle cells, where, in turn, the desmin filaments.Through the desmosomes, the intermediate filaments of adjacent cells connect to a large network that spreads across several cells of the same tissue.→ Where are demossomes found and what are their functions?
Demossomes are very common in epithelial cells, being numerous in the cells of the thorny stratum of the epidermis. In addition, it is possible to notice demossomes in the muscle cells, with some muscle strains involving the rupture of desmosomes.
The main function of desmosomes is to provide mechanical strength. This function is clearly observed with the analysis of a disease called pemphigus. In this disease, affected individuals have antibodies that attack the cadherin proteins, causing the desmosomes to break. As a result, the skin and mucosa cells detach, which results in the formation of bubbles and fluid leakage, thus showing the role of desmosomes in anchoring cells.
By Ma. Vanessa Sardinha dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-desmossomo.htm
