The sélectines are transmembrane Molécules which have with dimensions one of their extréminé N-terminal extracytoplasmic a sequence of the " type; lectine-like" who is able to recognize the glucidic determinants. These molecules thus enter concerned various phenomena:

- Intercellular recognitions.

- Phenomena of adhesion.

- The inhibition of contact.

Various types of sélectines

There are several types of sélectines. The 3 principal ones are:

- The sélectines of the type P : they are expressed on the surface of the plates which allow blood coagulation.

- The sélectines of the type E : they are expressed on the surface of the cells endothéliales .

- The sélectines of the type L : they are expressed on the surface of the leucocytes , it is they which allow the phenomenon of " aiming ".

Functions of the sélectines

The sélectines intervene in many phenomena. They specifically recognize the parts of the glycanes types present on the other cells, and carry out heterophilic connections. They allow for example the recognition between the Leucocytes and the cells endothéliales.

They allow weak phenomena of adhesions but of very high specificity.

They are not present permanently, and they can be induced: they are present in blisters inside the cell and when the cell is stimulated, these blisters migrate on the surface. The exposure of the sélectines on the extracytoplasmic face of the plasmic membrane is fast (a few minutes).

The inhibition of contact

They intervene in a phenomenon particulie: the Inhibition of contact. In one limps of culture, one notices that the cells stop proliferating when all the surface of limps is filled. That signifi that a message can pass from cells in cells in order to stoper the proliferation.

This message is médié by the sélectines.