scholarly journals Small Mass but Strong Information: Diagnostic Ions Provide Crucial Clues to Correctly Identify Histone Lysine Modifications

Proteomes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 18
Author(s):  
Alaa Hseiky ◽  
Marion Crespo ◽  
Sylvie Kieffer-Jaquinod ◽  
François Fenaille ◽  
Delphine Pflieger

(1) Background: The proteomic analysis of histones constitutes a delicate task due to the combination of two factors: slight variations in the amino acid sequences of variants and the multiplicity of post-translational modifications (PTMs), particularly those occurring on lysine residues. (2) Methods: To dissect the relationship between both aspects, we carefully evaluated PTM identification on lysine 27 from histone H3 (H3K27) and the artefactual chemical modifications that may lead to erroneous PTM determination. H3K27 is a particularly interesting example because it can bear a range of PTMs and it sits nearby residues 29 and 31 that vary between H3 sequence variants. We discuss how the retention times, neutral losses and immonium/diagnostic ions observed in the MS/MS spectra of peptides bearing modified lysines detectable in the low-mass region might help validate the identification of modified sequences. (3) Results: Diagnostic ions carry key information, thereby avoiding potential mis-identifications due to either isobaric PTM combinations or isobaric amino acid-PTM combinations. This also includes cases where chemical formylation or acetylation of peptide N-termini artefactually occurs during sample processing or simply in the timeframe of LC-MS/MS analysis. Finally, in the very subtle case of positional isomers possibly corresponding to a given mass of lysine modification, the immonium and diagnostic ions may allow the identification of the in vivo structure.

2016 ◽  
Author(s):  
Wesley G. Chen ◽  
Jacob Witten ◽  
Scott C. Grindy ◽  
Niels Holten-Andersen ◽  
Katharina Ribbeck

AbstractThe nuclear pore complex controls the passage of molecules via hydrophobic phenylalanine-glycine (FG) domains on nucleoporins. Such FG-domains consist of repeating units of FxFG, FG, or GLFG sequences, which can be interspersed with highly charged amino acid sequences. Despite the high density of charge exhibited in certain FG-domains, if and how charge influences FG-domain self-assembly and selective binding of nuclear transport receptors is largely unexplored. Studying how individual charged amino acids contribute to nuclear pore selectivity is challenging with modern in vivo and in vitro techniques due to the complexity of nucleoporin sequences. Here, we present a rationally designed approach to deconstruct essential components of nucleoporins down to 14 amino acid sequences. With these nucleoporin-based peptides, we systematically dissect how charge type and placement of charge influences self-assembly and selective binding of FG-containing gels. Specifically, we find that charge type determines which hydrophobic substrates FG sequences recognize while spatial localization of charge tunes hydrophobic self-assembly and receptor selectivity of FG sequences.


1986 ◽  
Vol 238 (1) ◽  
pp. 305-308 ◽  
Author(s):  
D A D Parry ◽  
J F Conway ◽  
P M Steinert

Analysis of the amino acid sequences of lamins A and C has revealed that each chain has an almost continuous heptad-containing coiled-coil domain containing structural regularities in the linear disposition of the acidic and the basic residues. The data suggest that the lamin molecules are two-stranded ropes, that the two chains are parallel to one another and in axial register, and that the molecules aggregate in vivo through periodic ionic interactions. These results indicate that significant changes in stability of the nuclear envelope may be achieved between interphase and mitosis through changes in the degree of phosphorylation of the lamin proteins.


2002 ◽  
Vol 29 (10) ◽  
pp. 1131 ◽  
Author(s):  
Xiao-Ping Li ◽  
Alba Phippard ◽  
Jae Pasari ◽  
Krishna K. Niyogi

In land plants, photosystem II subunit S (PsbS) plays a key role in xanthophyll- and pH-dependent non-photochemical quenching (qE) of excess absorbed light energy. Arabidopsis thaliana (L.) Heynh. npq4 mutants are defective in the psbS gene and have impaired qE. Exactly how the PsbS protein is involved in qE is unclear, but it has been proposed that PsbS binds H+ and/or de-epoxidized xanthophylls in excess light as part of the qE mechanism. To identify amino acid residues that are important for PsbS function, we sequenced the psbS gene from eight npq4 point mutant alleles isolated by forward genetics screening, including two new alleles. In the four transmembrane helices of PsbS, several amino acid residues were found to affect the stability and/or function of the protein. By comparing the predicted amino acid sequences of PsbS from several plant species and studying the proposed topological structure of PsbS, eight possible H+-binding amino acid residues on the lumenal side of the protein were identified and then altered by site-directed mutagenesis in vitro. The mutant psbS genes were transformed into npq4-1, a psbS deletion mutant, to test the stability and function of the mutant PsbS proteins in�vivo. The results demonstrate that two conserved, protonatable amino acids, E122 and E226, are especially critical for the function of PsbS.


2019 ◽  
Author(s):  
Taraneh Zarin ◽  
Bob Strome ◽  
Alex N Nguyen Ba ◽  
Simon Alberti ◽  
Julie D Forman-Kay ◽  
...  

AbstractIntrinsically disordered regions make up a large part of the proteome, but the sequence-to-function relationship in these regions is poorly understood, in part because the primary amino acid sequences of these regions are poorly conserved in alignments. Here we use an evolutionary approach to detect molecular features that are preserved in the amino acid sequences of orthologous intrinsically disordered regions. We find that most disordered regions contain multiple molecular features that are preserved, and we define these as “evolutionary signatures” of disordered regions. We demonstrate that intrinsically disordered regions with similar evolutionary signatures can rescue functionin vivo,and that groups of intrinsically disordered regions with similar evolutionary signatures are strongly enriched for functional annotations and phenotypes. We propose that evolutionary signatures can be used to predict function for many disordered regions from their amino acid sequences.


2011 ◽  
Vol 365 (1-2) ◽  
pp. 76-86 ◽  
Author(s):  
Cindy L. Zuleger ◽  
Michael D. Macklin ◽  
Bret L. Bostwick ◽  
Qinglin Pei ◽  
Michael A. Newton ◽  
...  

1971 ◽  
Vol 121 (3) ◽  
pp. 439-446 ◽  
Author(s):  
E. W. Thompson ◽  
M. Richardson ◽  
D. Boulter

The amino acid sequences of sesame (Sesamum indicum L.) and castor (Ricinus communis L.) cytochrome c were determined by using 1.5μmol of protein from each species. Both molecules consist of a single chain of 111 amino acid residues and are homologous with other mitochondrial cytochrome c molecules. Both have an N-acetylated ‘tail’ of eight amino acids and two ∈-N-trimethyl-lysine residues, as also reported for wheat germ (Delange, Glazer & Smith, 1969) and mung-bean cytochrome c (Thompson, Laycock, Ramshaw & Boulter, 1970). Two different preparations of castor cytochrome c differed by one residue. This was glutamic acid for glutamine in position 100. The results for sesame and castor cytochrome c led to a re-examination and subsequent correction to the N-terminal region of the mung-bean cytochrome c sequence, as given by Thompson et al. (1970).


2002 ◽  
Vol 83 (8) ◽  
pp. 2075-2083 ◽  
Author(s):  
Cho-Hua Wan ◽  
Maria Söderlund-Venermo ◽  
David J. Pintel ◽  
Lela K. Riley

Rodent parvoviruses have been documented to interfere with both in vivo and in vitro research. In this study, three rat parvoviruses distinct from previously characterized rodent parvoviruses were identified from naturally infected rats obtained from four discrete sources. These three newly recognized parvoviruses were designated rat minute virus (RMV)-1a, -1b and -1c. In this study, the genomic nucleotide sequence and the predicted amino acid sequences of proteins for each of the three RMV-1 variants and Kilham rat virus (KRV) were determined and compared with previously characterized rodent parvoviruses. The three RMV-1 variants were shown to be closely related to each other, to be distinct from but closely related to KRV and H-1 virus, and to be significantly different from the previously identified rat parvovirus isolate, RPV-1a.


2008 ◽  
Vol 190 (21) ◽  
pp. 7035-7042 ◽  
Author(s):  
Marcus Thein ◽  
Ignas Bunikis ◽  
Katrin Denker ◽  
Christer Larsson ◽  
Sally Cutler ◽  
...  

ABSTRACT Relapsing fever is a worldwide, endemic disease caused by several spirochetal species belonging to the genus Borrelia. During the recurring fever peaks, borreliae proliferate remarkably quickly compared to the slow dissemination of Lyme disease Borrelia and therefore require efficient nutrient uptake from the blood of their hosts. This study describes the identification and characterization of the first relapsing fever porin, which is present in the outer membranes of B. duttonii, B. hermsii, B. recurrentis, and B. turicatae. The pore-forming protein was purified by hydroxyapatite chromatography and designated Oms38, for outer membrane-spanning protein of 38 kDa. Biophysical characterization of Oms38 was done by using the black lipid bilayer method, demonstrating that Oms38 forms small, water-filled channels of 80 pS in 1 M KCl that did not exhibit voltage-dependent closure. The Oms38 channel is slightly selective for anions and shows a ratio of permeability for cations over anions of 0.41 in KCl. Analysis of the deduced amino acid sequences demonstrated that Oms38 contains an N-terminal signal sequence which is processed under in vivo conditions. Oms38 is highly conserved within the four studied relapsing fever species, sharing an overall amino acid identity of 58% and with a strong indication for the presence of amphipathic β-sheets.


1992 ◽  
Vol 286 (3) ◽  
pp. 923-927 ◽  
Author(s):  
R Myllylä ◽  
V Günzler ◽  
K I Kivirikko ◽  
D D Kaska

A search for conserved amino acid residues within the cDNA-derived amino acid sequences of 2-oxoglutarate-coupled dioxygenases revealed the presence of two distinct motifs, spaced 49-71 amino acids apart, toward the C-terminal regions of these proteins. Each of the two common motifs contains an invariant histidine residue at a conserved position. The 2-oxoglutarate-coupled dioxygenases function in diverse processes, including the post-translational hydroxylation of proline and lysine residues in vertebrate collagens and the biosynthesis of microbial cephalosporins, yet they have a common reaction mechanisms, which requires the binding of Fe2+, 2-oxoglutarate, O2 and ascorbate at the catalytic site. The two regions of homology, and specifically the identical histidines, potentially represent functionally important sites related to their catalytic activity. Modification of histidine residues by diethyl pyrocarbonate inactivated vertebrate and algal prolyl 4-hydroxylase and vertebrate lysyl hydroxylase, indicating that histidine residues function in the catalytic site of these 2-oxoglutarate-coupled dioxygenases. Inactivation was prevented by the presence of co-substrates, but not by the peptide substrate. It is proposed that the histidine residues in the conserved motifs may function as Fe(2+)-binding ligands.


2010 ◽  
Vol 76 (23) ◽  
pp. 7811-7819 ◽  
Author(s):  
Jing Han ◽  
Jing Hou ◽  
Hailong Liu ◽  
Shuangfeng Cai ◽  
Bo Feng ◽  
...  

ABSTRACT Polyhydroxyalkanoates (PHAs) are accumulated as intracellular carbon and energy storage polymers by various bacteria and a few haloarchaea. In this study, 28 strains belonging to 15 genera in the family Halobacteriaceae were investigated with respect to their ability to synthesize PHAs and the types of their PHA synthases. Fermentation results showed that 18 strains from 12 genera could synthesize polyhydroxybutyrate (PHB) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). For most of these haloarchaea, selected regions of the phaE and phaC genes encoding PHA synthases (type III) were cloned via PCR with consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) and were sequenced. The PHA synthases were also examined by Western blotting using haloarchaeal Haloarcula marismortui PhaC (PhaCHm) antisera. Phylogenetic analysis showed that the type III PHA synthases from species of the Halobacteriaceae and the Bacteria domain clustered separately. Comparison of their amino acid sequences revealed that haloarchaeal PHA synthases differed greatly in both molecular weight and certain conserved motifs. The longer C terminus of haloarchaeal PhaC was found to be indispensable for its enzymatic activity, and two additional amino acid residues (C143 and C190) of PhaCHm were proved to be important for its in vivo function. Thus, we conclude that a novel subtype (IIIA) of type III PHA synthase with unique features that distinguish it from the bacterial subtype (IIIB) is widely distributed in haloarchaea and appears to be involved in PHA biosynthesis.


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