title: Acetylation within the First 17 Residues of Huntingtin Exon 1 Alters Aggregation and Lipid Binding.
abstract: Huntington's disease (HD) is a genetic neurodegenerative disorder caused by an expanded polyglutamine (polyQ) domain near the N-terminus of the huntingtin (htt) protein. Expanded polyQ leads to htt aggregation. The first 17 amino acids (Nt(17)) in htt comprise a lipid-binding domain that undergoes a number of posttranslational modifications that can modulate htt toxicity and subcellular localization. As there are three lysines within Nt(17), we evaluated the impact of lysine acetylation on htt aggregation in solution and on model lipid bilayers. Acetylation of htt-exon1(51Q) and synthetic truncated htt-exon 1 mimicking peptides (Nt(17)-Q35-P10-KK) was achieved using a selective covalent label, sulfo-N-hydroxysuccinimide (NHSA). With this treatment, all three lysine residues (K6, K9, and K15) in Nt(17) were significantly acetylated. N-terminal htt acetylation retarded fibril formation in solution and promoted the formation of larger globular aggregates. Acetylated htt also bound lipid membranes and disrupted the lipid bilayer morphology less aggressively compared with the wild-type. Computational studies provided mechanistic insights into how acetylation alters the interaction of Nt(17) with lipid membranes. Our results highlight that N-terminal acetylation influences the aggregation of htt and its interaction with lipid bilayers.
authors.affiliation: The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia.
authors.forename: Maxmore
authors.initials: M
authors.lastname: Chaibva
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.
authors.forename: Sudi
authors.initials: S
authors.lastname: Jawahery
authors.affiliation: The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia.
authors.forename: Albert W
authors.initials: AW
authors.lastname: Pilkington
authors.affiliation: The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia.
authors.forename: James R
authors.initials: JR
authors.lastname: Arndt
authors.affiliation: The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia.
authors.forename: Olivia
authors.initials: O
authors.lastname: Sarver
authors.affiliation: The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Valentine
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, Maryland; Biophysics Program, Institute for Physical Chemistry and Technology, University of Maryland, College Park, Maryland. Electronic address: matysiak@umd.edu.
authors.forename: Silvina
authors.initials: S
authors.lastname: Matysiak
authors.affiliation: The C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia; NanoSAFE, West Virginia University, Morgantown, West Virginia; Center for Neurosciences, West Virginia University, Morgantown, West Virginia. Electronic address: justin.legleiter@mail.wvu.edu.
authors.forename: Justin
authors.initials: J
authors.lastname: Legleiter
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D005091:Exons; D000071058:Huntingtin Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D051379:Mice; D010455:Peptides / Q000378:metabolism; D066329:Protein Aggregates
chemical_list: D000071058:Huntingtin Protein; D008051:Lipid Bilayers; D010455:Peptides; D066329:Protein Aggregates; C097188:polyglutamine