Plectin may have a role in cross-linking intermediate filaments, in inter-linking intermediate filaments with microtubules and microfilaments and in anchoring intermediate filaments to the plasma and nuclear membranes. Plectin is recruited into hemidesmosomes, multiprotein complexes that facilitate adhesion of epithelia to the basement membrane, thereby providing linkage between the intracellular … expand

Plectin may have a role in cross-linking intermediate filaments, in inter-linking intermediate filaments with microtubules and microfilaments and in anchoring intermediate filaments to the plasma and nuclear membranes. Plectin is recruited into hemidesmosomes, multiprotein complexes that facilitate adhesion of epithelia to the basement membrane, thereby providing linkage between the intracellular keratin filaments to the laminins of the extracellular matrix. Plectin binds to hemidesmosomes through association of its actin-binding domain with the first pair of fibronectin type III repeats and a small part of the connecting segment of the integrin-beta4 subunit, the latter (integrin-alpha6,beta4) acting as a receptor for the extracellular matrix component laminin-5.

The plectin repeat is also seen in the cell adhesion junction plaque proteins, desmoplakin, envoplakin, and bullous pemphigoid antigen. The domains in plakins show considerable sequence homology. The N terminus consists of a plakin domain containing a number of subdomains with high α-helical content, while the central coiled-coil domain is composed of heptad repeats involved in the dimerisation of plakin, and the C terminus contains one or more homologous repeat sequences referred to plectin repeats [ PUBMED:14668477 ]. This entry represents the plectin repeats found in the C terminus of plakin proteins.