Pad2 deletion induces anxiety‑like behaviors and memory deficits in mice

Citrullination, the deimination of peptidylarginine residues into peptidylcitrulline catalyzed by the peptidylarginine deiminase (PADs), has been confirmed as a unique form of posttranslational modification of proteins. Among the five isoforms of PADs, PAD2 is a main PAD enzyme expressed in central nervous system (CNS). Previous studies reported that citrullinated proteins catalyzed by PAD2 was increasingly associated with neurological disorders such as Alzheimer's disease, prion disease and Multiple Sclerosis. However, the physiological role of PAD2 in the CNS are still poorly elucidated. Here we reported that Pad2 knockout (KO) mice exhibited significantly increased anxiety level and impaired memory capacity. Furthermore, Western Blot analysis, immunohistochemistry and proteomics revealed alterations in synaptic-related proteins and dendritic spines in hippocampus of Pad2 KO animals. These findings indicated that Pad2 plays an important function in the CNS, which is implicated in the regulation of emotion and cognitive capacity.