MRG (IPR008676)

Short name: MRG

Overlapping homologous superfamilies


Family relationships


This entry represents MRG protein family, whose members include MORF4L1/2 (MRG15/MRGX) and MSL3L1/2 from humans, ESA1-associated factor 3 (Eaf3) from yeasts and male-specific lethal 3 (MSL3) from flies. They contain an N-terminal chromodomain that binds H3K36me3, a histone mark associated with transcription elongation [PMID: 22285924].

Saccharomyces cerevisiae Eaf3 is a component of both NuA4 histone acetyltransferase and Rpd3S histone deacetylase complexes [PMID: 12773392, PMID: 2662307]. It was found that Eaf3 mediates preferential deacetylation of coding regions through an interaction between the Eaf3 chromodomain and methylated H3-K36 that presumably results in preferential association of the Rpd3 complex [PMID: 16364921].

The Drosophila MSL proteins (MSL1, MSL2, MSL3, MLE, and MOF) are essential for elevating transcription of the single X chromosome in the male (X chromosome dosage compensation) [PMID: 22421046]. Together with two partly redundant non-coding RNAs, roX1 and roX2, they form the MSL complex, also known as dosage compensation complex or DCC. MSL complex upregulates transcription by spreading the histone H4 Lys16 (H4K16) acetyl mark [PMID: 20657587] and allows compensation for the loss of one X-chromosomal allele by increasing the transcription from the retained allele [PMID: 17173057]. The MSL3 chromodomain has been shown to bind DNA and methylated H4K20 in vitro [PMID: 20657587].

Human MORF4L1, also known as MRG15, is a component of the NuA4 histone acetyltransferase complex that transcriptional activates genes by acetylation of nucleosomal histones H4 and H2A. This modification may both alter nucleosome - DNA interactions and promote interaction of the modified histones with other proteins which positively regulate transcription. NuA4 complex may also play a direct role in DNA repair when directly recruited to sites of DNA damage. MRG15 is also a component of the mSin3A/Pf1/HDAC complex which acts to repress transcription by deacetylation of nucleosomal histones. MRG15 was found to interact with PALB2, a tumour suppressor protein that plays a crucial role in DNA damage repair by homologous recombination [PMID: 20536842]. Furthermore, MRG15 play a role in the response to double strand breaks (DSBs) by recruiting the BRCA complex (BRCA1, PALB2, BRCA2 and RAD51) to sites of damaged DNA [PMID: 14966270, PMID: 20332121].

GO terms

Biological Process

GO:0006325 chromatin organization
GO:0006355 regulation of transcription, DNA-templated

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.