4. Hemidesmosomes
Hemidesmosomes (hemi- _ half) resemble desmosomes, but
they do not link adjacent cells. The name arises from the fact that
they look like half of a desmosome. However, the transmembrane glycoproteins in hemidesmosomes are integrins rather than cadherins. On the inside of the plasma membrane, integrins attach to intermediate filaments made of the protein keratin. On the outside of the plasma membrane, the integrins attach to the protein laminin, which is present in the basement membrane (discussed shortly). Thus, hemidesmosomes anchor cells not to each other but to the basement membrane.