title: O-Linked β-N-acetylglucosamine (O-GlcNAc) regulates emerin binding to barrier to autointegration factor (BAF) in a chromatin- and lamin B-enriched "niche".
abstract: Emerin, a membrane component of nuclear "lamina" networks with lamins and barrier to autointegration factor (BAF), is highly O-GlcNAc-modified ("O-GlcNAcylated") in mammalian cells. Mass spectrometry analysis revealed eight sites of O-GlcNAcylation, including Ser-53, Ser-54, Ser-87, Ser-171, and Ser-173. Emerin O-GlcNAcylation was reduced ~50% by S53A or S54A mutation in vitro and in vivo. O-GlcNAcylation was reduced ~66% by the triple S52A/S53A/S54A mutant, and S173A reduced O-GlcNAcylation of the S52A/S53A/S54A mutant by ~30%, in vivo. We separated two populations of emerin, A-type lamins and BAF; one population solubilized easily, and the other required sonication and included histones and B-type lamins. Emerin and BAF associated only in histone- and lamin-B-containing fractions. The S173D mutation specifically and selectively reduced GFP-emerin association with BAF by 58% and also increased GFP-emerin hyper-phosphorylation. We conclude that β-N-acetylglucosaminyltransferase, an essential enzyme, controls two regions in emerin. The first region, defined by residues Ser-53 and Ser-54, flanks the LEM domain. O-GlcNAc modification at Ser-173, in the second region, is proposed to promote emerin association with BAF in the chromatin/lamin B "niche." These results reveal direct control of a conserved LEM domain nuclear lamina component by β-N-acetylglucosaminyltransferase, a nutrient sensor that regulates cell stress responses, mitosis, and epigenetics.
authors.affiliation: From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Berk
authors.affiliation: the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904.
authors.forename: Sushmit
authors.initials: S
authors.lastname: Maitra
authors.affiliation: the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Dawdy
authors.affiliation: the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Shabanowitz
authors.affiliation: the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904.
authors.forename: Donald F
authors.initials: DF
authors.lastname: Hunt
authors.affiliation: From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and. Electronic address: klwilson@jhmi.edu.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Wilson
mesh_terms: D000117:Acetylglucosamine; D000215:Acylation / Q000502:physiology; D019943:Amino Acid Substitution; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007797:Laminin / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D020125:Mutation, Missense; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D034881:Nuclear Lamina / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology
chemical_list: C501959:BANF1 protein, human; D002843:Chromatin; D004268:DNA-Binding Proteins; D006657:Histones; D007797:Laminin; D008565:Membrane Proteins; D009687:Nuclear Proteins; C092710:emerin; D017351:N-Acetylglucosaminyltransferases; D000117:Acetylglucosamine
keywords: Cardiomyopathy; Chromosomes/Non-histone Chromosomal Proteins; Emerin; Lamin; Laminopathy; Muscular Dystrophy; Nuclear Matrix; Nuclear Membrane; Nucleoskeleton; O-GlcNAc