ABSTRACT
Peptidylarginine deiminase enzymes (PADs) convert arginine residues to citrulline in a process called citrullination or deimination. Recently, two PADs, PAD2 and PAD4, have been linked to hormone signaling in vitro and the goal of this study was to test for links between PAD2/PAD4 and hormone signaling in vivo. Preliminary analysis of Padi2 and Padi4 single knockout (SKO) mice did not find any overt reproductive defects and we predicted that this was likely due to genetic compensation. To test this hypothesis, we created a Padi2/Padi4 double knockout (DKO) mouse model and tested these mice for a range of reproductive defects. Results from controlled breeding trials found that DKO breeding pairs appeared to take longer to have their first litter than WT controls and that DKO male weanlings weighed significantly less than their WT counterparts. Additionally, DKO males took significantly longer than WT males to reach puberty and had lower serum testosterone levels. Furthermore, DKO males had smaller testes than WT males with increased rates of germ cell apoptosis. The DKO mouse model provides a new tool for investigating PAD function and outcomes from our studies provide the first in vivo evidence linking PADs with hormone signaling.
Competing Interest Statement
The authors have declared no competing interest.