Peptidylarginine deiminase type 4 (PAD4)

Peptidylarginine deiminase type 4 (PAD4) is a calcium-dependent enzyme that catalyzes the conversion of arginine residues to citrulline in proteins, a post-translational modification known as citrullination or deimination[1][4][5][7]. PAD4 is uniquely present in both the cytoplasm and nucleus of certain hematopoietic cells, including neutrophils and granulocytes, where it plays a central role in immune responses and in chromatin remodeling through histone modification[3][5]. PAD4 activity is implicated in the formation of neutrophil extracellular traps (NETs) as well as in the regulation of gene expression via histone citrullination, which can antagonize arginine methylation[3][4]. Genetic polymorphisms and abnormal activation of PAD4 have been linked to autoimmune diseases such as rheumatoid arthritis (where anti-citrullinated peptide antibodies serve as biomarkers), as well as to cancer and cardiovascular disease development[4][6]. PAD4 is being actively investigated as a therapeutic target, with several classes of small-molecule inhibitors under development or in preclinical testing[4][5].

Other names

Protein-arginine deiminase type-4PADI4PAD IV

Enzyme inhibition (blockade of citrullination/deimination activity)