Peptidyl arginine deiminase type I (PADI1)

Peptidyl arginine deiminase type I (PADI1) is a calcium-dependent enzyme belonging to the peptidyl arginine deiminase family, catalyzing the post-translational deimination (citrullination) of arginine residues into citrulline in target proteins. PADI1 is primarily expressed in the epidermis, where it deiminates filaggrin and keratin K1, supporting hydration and the barrier function of the stratum corneum, and may be involved in hair follicle formation. PADI1 also plays a role in chromatin remodeling and early embryonic development via histone citrullination, with loss of function leading to developmental arrest in mouse embryos. Aberrant PADI1 expression or activity has been implicated in cancer, including OSCC and triple negative breast cancer, and may serve as a tissue biomarker. While PADI1 is a valid therapeutic target by analogy to other PADIs, specific clinical inhibitors have not been established. Safety considerations include the risk of compromising skin barrier integrity or embryonic development from enzyme inhibition.

Other names

Protein-arginine deiminase type-1PAD1PDI1HPAD10PDIPeptidylarginine deiminase IhPAD-colony 10peptidyl arginine deiminase, type Ipeptidylarginine deiminase type I

Enzyme inhibitors targeting PADI1 block the citrullination of arginine residues on protein substrates, affecting protein structure/function and possibly chromatin state.