SPR-1/CoREST facilitates the maternal epigenetic reprogramming of the histone demethylase SPR-5/LSD1.

Maternal reprogramming of histone methylation is critical for reestablishing totipotency in the zygote, but how histone-modifying enzymes are regulated during maternal reprogramming is not well characterized. To address this gap, we asked whether maternal reprogramming by the H3K4me1/2 demethylase SPR-5/LSD1/KDM1A, is regulated by the chromatin co-repressor protein, SPR-1/CoREST, in Caenorhabditis elegans and mice. In C. elegans, SPR-5 functions as part of a reprogramming switch together with the H3K9 methyltransferase MET-2. By examining germline development, fertility, and gene expression in double mutants between spr-1 and met-2, as well as fertility in double mutants between spr-1 and spr-5, we find that loss of SPR-1 results in a partial loss of SPR-5 maternal reprogramming function. In mice, we generated a separation of function Lsd1 M448V point mutation that compromises CoREST binding, but only slightly affects LSD1 demethylase activity. When maternal LSD1 in the oocyte is derived exclusively from this allele, the progeny phenocopy the increased perinatal lethality that we previously observed when LSD1 was reduced maternally. Together, these data are consistent with CoREST having a conserved function in facilitating maternal LSD1 epigenetic reprogramming.