Global profiling of protein lactylome in porcine granulosa cells.

Background: In mammals, granulosa cells (GCs) use glycolysis as the main energy source for oocyte development. Lactate, the end product of glycolysis, covalently binds lysine. Residues in proteins through an enzymatic or non-enzymatic method known as lysine lactylation (Kla), which plays a role in epigenetics. Histone lactylation positively regulates reproduction. However, the roles of non-histone proteins in reproduction remain unclear. Based on the abundance of lactate in GCs, we first profiled the global lactylome in porcine GCs.

Results: We identified 24,038 lactylation sites in 6,255 proteins, the largest number to date, indicating the richness of lactylation in GCs. Histones from porcine, humans, and mice are conserved at most sites, with some sites being specific to porcine such as H4K79. Kla proteins were significantly enriched in energy metabolism-related pathways, with all the enzymes involved in the tricarboxylic acid cycle and glycolysis undergoing lactylation. We also preliminarily illustrated the mechanism by which decreased protein lactylation induces ferroptosis.

Conclusions: Our study provides a comprehensive understanding of lactylation in mammalian GCs and lays the foundation for subsequent studies on the lactylation-mediated regulation of female reproductive function.