Involucrin (INV)

Involucrin is a protein component of human skin. In binding the protein loricrin, involucrin contributes to the formation of a cell envelope that protects corneocytes in the skin.It is the Part of the insoluble cornified cell envelope (CE) of stratified squamous epithelia. Expressed in keratinocytes of epidermis and other stratified squamous epithelia.

Involucrin is a highly reactive, soluble, transglutaminase substrate protein present in keratinocytes of epidermis and other stratified squamous epithelia. It first appears in the cell cytosol, but ultimately becomes cross-linked to membrane proteins by transglutaminase thus helping in the formation of an insoluble envelope beneath the plasma membrane functioning as a glutamyl donor during assembly of the cornified envelope.

Involucrin is synthesised in the stratum spinosum and cross linked in the stratum granulosum by the transglutaminase enzyme that makes it highly stable. Thus it provides structural support to the cell, thereby allowing the cell to resist invasion by micro-organisms.

Apigenin, a plant-derived flavanoid that has significant promise as a skin cancer chemopreventiveagent, has been found to regulate normal human keratinocyte differentiation by suppressing involucrin, and this is associated with reduced cell proliferation without apoptosis.