Envoplakin

Envoplakin is a protein that in humans is encoded by the EVPL gene. Envoplakin is a member of the plakin family of proteins, which play a critical role in cell adhesion and structural integrity within the epidermis and other epithelial tissues. As a component of the desmosome complexes, envoplakin is essential for the proper function of these cell structures, which are crucial for the mechanical resilience and cohesion of epithelial layers.

Function

Envoplakin, along with other plakin family members such as periplakin and desmoplakin, is involved in linking the cytoskeleton to the cell membrane in epithelial cells. It is particularly important in the formation and maintenance of the cornified envelope, a structure that provides a barrier against environmental damage in the outermost layers of the skin. Envoplakin has a rod domain that mediates its integration into the desmosomal plaque and a carboxy-terminal domain that is important for the assembly of the cornified envelope.

Structure

The envoplakin protein is characterized by a plakin domain at its amino terminus, a series of repeating units known as plakin repeat domains, and a globular carboxy terminus. This structure is typical of the plakin protein family, which is known for its ability to form dimers and link cytoskeletal structures to junctional complexes like desmosomes.

Clinical Significance

Mutations in the EVPL gene have been associated with several skin disorders, including pemphigus vulgaris and paraneoplastic pemphigus, autoimmune diseases characterized by blistering of the skin and mucous membranes. The role of envoplakin in the integrity of the epidermal barrier makes it a target for autoantibodies in these conditions, leading to the disruption of cell adhesion and the clinical manifestations of the diseases.

Research

Research on envoplakin continues to uncover its roles not only in skin diseases but also in the normal functioning of the skin barrier. Studies have explored its interaction with other proteins and its role in cellular processes such as signal transduction, cell migration, and wound healing. Understanding the molecular mechanisms underlying envoplakin's functions may lead to new therapeutic approaches for skin diseases and conditions affecting epithelial integrity.