In Saccharomyces cerevisiae, Set1p-mediated deposition of trimethylation on lysine 4 of histone H3 is a histone modification often associated with active transcription. Recently, it was discovered that members of the Jumonji family of proteins have the enzymatic ability to remove methylation on histone lysine residues. Here, I describe the function of the yeast Jumonji protein Jhd2p, the only yeast Jumonji with known demethylase activity towards histone H3 lysine 4 methylation. I find that during the development program of yeast sporulation, Jhd2p is responsible for demethylating lysine 4 on a global scale. Further, ChIP analysis examining lysine 4 methylation levels reveals that genes whose expression is dependent on JHD2 during sporulation are subject to what appears to be Jhd2p-mediated demethylation. Additionally, synthetic dosage lethality screens performed to identify genetic interactors of Jhd2p revealed that Jhd2p is a likely component of mitochondrial retrograde signaling, working alongside the transcription factors Rtg1p/Rtg3p.

In Saccharomyces cerevisiae, Set1p-mediated deposition of trimethylation on lysine 4 of histone H3 is a histone modification often associated with active transcription. Recently, it was discovered that members of the Jumonji family of proteins have the enzymatic ability to remove methylation on histone lysine residues. Here, I describe the function of the yeast Jumonji protein Jhd2p, the only yeast Jumonji with known demethylase activity towards histone H3 lysine 4 methylation. I find that during the development program of yeast sporulation, Jhd2p is responsible for demethylating lysine 4 on a global scale. Further, ChIP analysis examining lysine 4 methylation levels reveals that genes whose expression is dependent on JHD2 during sporulation are subject to what appears to be Jhd2p-mediated demethylation. Additionally, synthetic dosage lethality screens performed to identify genetic interactors of Jhd2p revealed that Jhd2p is a likely component of mitochondrial retrograde signaling, working alongside the transcription factors Rtg1p/Rtg3p.