Drosophila KDM2 is a H3K4me3 demethylase regulating nucleolar organization

Abstract

BackgroundCG11033 (dKDM2) is the Drosophila homolog of the gene KDM2B. dKDM2 has been known to possess histone lysine demethylase activity towards H3K36me2 in cell lines and it regulates H2A ubiquitination. The human homolog of the gene has dual activity towards H3K36me2 as well as H3K4me3, and plays an important role in cellular senescence.FindingsWe have used transgenic flies bearing an RNAi construct for the dKDM2 gene. The knockdown of dKDM2 gene was performed by crossing UAS-RNAi-dKDM2 flies with actin-Gal4 flies. Western blots of acid extracted histones and immunofluoresence analysis of polytene chromosome showed the activity of the enzyme dKDM2 to be specific for H3K4me3 in adult flies. Immunofluoresence analysis of polytene chromosome also revealed the presence of multiple nucleoli in RNAi knockdown mutants of dKDM2 and decreased H3-acetylation marks associated with active transcription.ConclusionOur findings indicate that dKDM2 is a histone lysine demethylase with specificity for H3K4me3 and regulates nucleolar organization.

Discovering geometric patterns in genomic data

“…We can see that two h3k4me3s occur in all those 4 patterns, which indicates that the h3k4me3 has a positive impact on the gene expression. This is confirmed by the biological observations: h3k4me3 is an important epigenetic landmark for active transcription [15] [12].…”

The H3K4me3 Histone Demethylase Fbxl10 Is a Regulator of Chemokine Expression, Cellular Morphology, and the Metabolome of Fibroblasts

“…In agreement with our data, Frescas et al also observed H3K4me3 demethylase activity for Fbxl10 (12). This is further supported by a very recent publication analyzing the demethylase function of the Drosophila homolog dKdm2 which was described as a H3K4me3 demethylase in vivo (30). Nevertheless, it has to be considered that histone demethylases act in multienzyme complexes, and the specificity of histone modifiers may be dependent on interaction with other proteins or modifications on histone residues nearby (1,5).…”

A developmental genetic analysis of the lysine demethylase KDM2 mutations in Drosophila melanogaster

“…The Drosophila KDM2 (dKDM2) is the single homolog of the mammalian KDM2A and KDM2B (Fig. 1A) (Dui et al, 2012; Jin et al, 2004; Kavi and Birchler, 2009; Lagarou et al, 2008). Biochemical purification for dRING-associated proteins coupled with mass spectrometric analysis led to the identification of dKDM2 as a component of dRING-associated factors complex (dRAF), a Polycomb group (PcG) silencing complex composed of dRING, Posterior Sex Comb (PSC) and dKDM2 (Lagarou et al, 2008).…”

“…Depletion of KDM2B was also shown to significantly reduce H2A ubiquitination in mouse embryonic stem cells (Wu et al, 2013). However, knocking down dKDM2 in vivo using actin5C-Gal4 to drive the expression of dKdm2-dsRNA in the third instar larvae did not reveal any effects of dKDM2 depletion on the levels of H3K36me2, H3K9me2, and H3K4me2 assayed by Western blot and immunofluoresence staining; instead, a strong increase of H3K4me3 was observed, suggesting that dKDM2 specifically demethylates H3K4me3 in vivo (Kavi and Birchler, 2009). In addition, depletion of dKDM2 in salivary glands resulted in multiple nucleoli (Kavi and Birchler, 2009).…”

“…However, knocking down dKDM2 in vivo using actin5C-Gal4 to drive the expression of dKdm2-dsRNA in the third instar larvae did not reveal any effects of dKDM2 depletion on the levels of H3K36me2, H3K9me2, and H3K4me2 assayed by Western blot and immunofluoresence staining; instead, a strong increase of H3K4me3 was observed, suggesting that dKDM2 specifically demethylates H3K4me3 in vivo (Kavi and Birchler, 2009). In addition, depletion of dKDM2 in salivary glands resulted in multiple nucleoli (Kavi and Birchler, 2009). These observations are consistent to the role of KDM2B in repressing rRNA gene expression by demethylating H3K4me3 in nucleolus (Frescas et al, 2007).…”