Abstract
During mammalian embryo development, pluripotent epiblast cells diversify into the three primary germ layers, which will later give rise to all fetal and adult tissues. These processes involve profound transcriptional and epigenetic changes that require precise coordination. Peptidylarginine deiminase IV (PADI4) is a transcriptional regulator that is strongly associated with inflammation and carcinogenesis but whose physiological roles are less well understood. We previously found that Padi4 expression is associated with pluripotency. Here, we examined the role of PADI4 in maintaining the multi-lineage differentiation potential of mouse embryonic stem (ES) cells. Using bulk and single-cell transcriptomic analyses of embryoid bodies (EBs) derived from Padi4 knock-out (Padi4-KO) mouse ES cells, we find that PADI4 loss impairs mesoderm diversification and differentiation of cardimyocytes and endothelial cells. Additionally, Padi4 deletion leads to concerted downregulation of genes associated with polarized growth, sterol metabolism and the extracellular matrix (ECM). This study indicates a requirement for Padi4 in the specification of the mesodermal lineage and reports the Padi4 associated transcriptome, providing a platform for understanding the physiological functions of Padi4 in development and homeostasis. This article is part of the Theo Murphy meeting issue 'The virtues and vices of protein citrullination'.