scholarly journals Transiently structured head domains control intermediate filament assembly

2021 ◽  
Vol 118 (8) ◽  
pp. e2022121118 ◽  
Author(s):  
Xiaoming Zhou ◽  
Yi Lin ◽  
Masato Kato ◽  
Eiichiro Mori ◽  
Glen Liszczak ◽  
...  
Keyword(s):  
Isotope Labeling ◽  
Low Complexity ◽  
Spectroscopic Studies ◽  
Neurofilament Light ◽  
Filament Assembly ◽  
Head Domain ◽  
Segmental Isotope Labeling ◽  
Structural Assembly ◽  
Self Association ◽  
Spectral Patterns

Low complexity (LC) head domains 92 and 108 residues in length are, respectively, required for assembly of neurofilament light (NFL) and desmin intermediate filaments (IFs). As studied in isolation, these IF head domains interconvert between states of conformational disorder and labile, β-strand–enriched polymers. Solid-state NMR (ss-NMR) spectroscopic studies of NFL and desmin head domain polymers reveal spectral patterns consistent with structural order. A combination of intein chemistry and segmental isotope labeling allowed preparation of fully assembled NFL and desmin IFs that could also be studied by ss-NMR. Assembled IFs revealed spectra overlapping with those observed for β-strand–enriched polymers formed from the isolated NFL and desmin head domains. Phosphorylation and disease-causing mutations reciprocally alter NFL and desmin head domain self-association yet commonly impede IF assembly. These observations show how facultative structural assembly of LC domains via labile, β-strand–enriched self-interactions may broadly influence cell morphology.

scholarly journals Transiently structured head domains control intermediate filament assembly

2020 ◽  
Author(s):  
Xiaoming Zhou ◽  
Yi Lin ◽  
Glen Liszczak ◽  
Vasily Sysoev ◽  
Lillian Sutherland ◽  
...  
Keyword(s):  
Isotope Labeling ◽  
Low Complexity ◽  
Spectroscopic Studies ◽  
Neurofilament Light ◽  
Filament Assembly ◽  
Head Domain ◽  
Segmental Isotope Labeling ◽  
Structural Assembly ◽  
Self Association ◽  
Spectral Patterns

SummaryLow complexity (LC) head domains 92 and 108 residues in length are, respectfully, required for assembly of neurofilament light (NFL) and desmin intermediate filaments (IFs). As studied in isolation, these IF head domains interconvert between states of conformational disorder and labile, β-strand-enriched polymers. Solid state nuclear magnetic resonance (ss-NMR) spectroscopic studies of NFL and desmin head domain polymers reveal spectral patterns consistent with structural order. A combination of intein chemistry and segmental isotope labeling allowed preparation of fully assembled NFL and desmin IFs that could also be studied by ss-NMR. Assembled IFs revealed spectra overlapping with those observed for β-strand-enriched polymers formed from the isolated NFL and desmin head domains. Phosphorylation and disease causing mutations reciprocally alter NFL and desmin head domain self-association, yet commonly impede IF assembly. These observations show how facultative structural assembly of LC domains via labile, β-strand-enriched self-interactions may broadly influence cell morphology.

scholarly journals Structural characterization of the D290V mutation site in hnRNPA2 low-complexity–domain polymers

2018 ◽  
Vol 115 (42) ◽  
pp. E9782-E9791 ◽  
Author(s):  
Dylan T. Murray ◽  
Xiaoming Zhou ◽  
Masato Kato ◽  
Siheng Xiang ◽  
Robert Tycko ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Electrostatic Interactions ◽  
Rna Binding ◽  
Isotope Labeling ◽  
Rna Binding Proteins ◽  
Neurological Diseases ◽  
Low Complexity ◽  
Wild Type ◽  
Mutation Site ◽  
Self Association

Human genetic studies have given evidence of familial, disease-causing mutations in the analogous amino acid residue shared by three related RNA binding proteins causative of three neurological diseases. Alteration of aspartic acid residue 290 of hnRNPA2 to valine is believed to predispose patients to multisystem proteinopathy. Mutation of aspartic acid 262 of hnRNPA1 to either valine or asparagine has been linked to either amyotrophic lateral sclerosis or multisystem proteinopathy. Mutation of aspartic acid 378 of hnRNPDL to either asparagine or histidine has been associated with limb girdle muscular dystrophy. All three of these aspartic acid residues map to evolutionarily conserved regions of low-complexity (LC) sequence that may function in states of either intrinsic disorder or labile self-association. Here, we present a combination of solid-state NMR spectroscopy with segmental isotope labeling and electron microscopy on the LC domain of the hnRNPA2 protein. We show that, for both the wild-type protein and the aspartic acid 290-to-valine mutant, labile polymers are formed in which the LC domain associates into an in-register cross-β conformation. Aspartic acid 290 is shown to be charged at physiological pH and immobilized within the polymer core. Polymers of the aspartic acid 290-to-valine mutant are thermodynamically more stable than wild-type polymers. These observations give evidence that removal of destabilizing electrostatic interactions may be responsible for the increased propensity of the mutated LC domains to self-associate in disease-causing conformations.

scholarly journals A potential role for the COOH-terminal domain in the lateral packing of type III intermediate filaments.

1991 ◽  
Vol 114 (4) ◽  
pp. 773-786 ◽  
Author(s):  
P D Kouklis ◽  
T Papamarcaki ◽  
A Merdes ◽  
S D Georgatos
Keyword(s):  
Potential Role ◽  
Type Iii ◽  
Filament Assembly ◽  
Filament Bundles ◽  
Self Association ◽  
Specific Association ◽  
A Site ◽  
Idiotypic Antibody

To identify sites of self-association in type III intermediate filament (IF) proteins, we have taken an "anti-idiotypic antibody" approach. A mAb (anti-Ct), recognizing a similar feature near the end of the rod domain of vimentin, desmin, and peripherin (epsilon site or epsilon epitope), was characterized. Anti-idiotypic antibodies, generated by immunizing rabbits with purified anti-Ct, recognize a site (presumably "complementary" to the epsilon epitope) common among vimentin, desmin, and peripherin (beta site or beta epitope). The beta epitope is represented in a synthetic peptide (PII) modeled after the 30 COOH-terminal residues of peripherin, as seen by comparative immunoblotting assays. Consistent with the idea of an association between the epsilon and the beta site, PII binds in vitro to intact IF proteins and fragments containing the epsilon epitope, but not to IF proteins that do not react with anti-Ct. Microinjection experiments conducted in vivo and filament reconstitution assays carried out in vitro further demonstrate that "uncoupling" of this site-specific association (by competition with PII or anti-Ct) interferes with normal IF architecture, resulting in the formation of filaments and filament bundles with diameters much greater than that of the normal IFs. These thick fibers are very similar to the ones observed previously when a derivative of desmin missing 27 COOH-terminal residues was assembled in vitro (Kaufmann, E., K. Weber, and N. Geisler. 1985. J. Mol. Biol. 185:733-742). As a molecular explanation, we propose here that the epsilon and the beta sites of type III IF proteins are "complementary" and associate during filament assembly. As a result of this association, we further postulate the formation of a surface-exposed "loop" or "hairpin" structure that may sterically prevent inappropriate filament-filament aggregation and regulate filament thickness.

scholarly journals Structure of the two most C-terminal RNA recognition motifs of PTB using segmental isotope labeling

2005 ◽  
Vol 25 (1) ◽  
pp. 150-162 ◽  
Author(s):  
Francesca Vitali ◽  
Anke Henning ◽  
Florian C Oberstrass ◽  
Yann Hargous ◽  
Sigrid D Auweter ◽  
...  
Keyword(s):  
Isotope Labeling ◽  
Rna Recognition ◽  
Rna Recognition Motifs ◽  
Segmental Isotope Labeling ◽  
Recognition Motifs

Segmental isotope-labeling of the intrinsically disordered protein PQBP1

FEBS Letters ◽  
2014 ◽  
Vol 588 (24) ◽  
pp. 4583-4589 ◽  
Author(s):  
Yuko Nabeshima ◽  
Mineyuki Mizuguchi ◽  
Asagi Kajiyama ◽  
Hitoshi Okazawa
Keyword(s):  
Isotope Labeling ◽  
Intrinsically Disordered Protein ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Segmental Isotope Labeling

scholarly journals Assembly properties of dominant and recessive mutations in the small mouse neurofilament (NF-L) subunit.

1990 ◽  
Vol 111 (5) ◽  
pp. 2005-2019 ◽  
Author(s):  
S R Gill ◽  
P C Wong ◽  
M J Monteiro ◽  
D W Cleveland
Keyword(s):  
Amino Acids ◽  
Insertional Mutagenesis ◽  
Wild Type ◽  
Recessive Mutations ◽  
Filament Assembly ◽  
Head Domain ◽  
Filament Networks ◽  
Carboxy Terminal ◽  
Network Disruption ◽  
Dominant Mutants

We have generated a set of amino- and carboxy-terminal deletions of the NF-L neurofilament gene and determined the assembly properties of the encoded subunits after coexpression with vimentin or wild-type NF-L. NF-L molecules missing greater than 30% (31 amino acids of the head) or 90% (128 amino acids of the tail) failed to incorporate into intermediate filament networks. Carboxy-terminal deletions into the rod domain yield dominant mutants that disrupt arrays assembled from wild-type subunits, even when present at levels of approximately 2% of the wild-type subunits. Even mutants retaining 55% of the tail (61 amino acids) disrupt normal arrays when accumulated above approximately 10% of wild-type subunits. Since deletion of greater than 90% of the head domain produces "recessive" assembly incompetent subunits that do not affect wild-type filament arrays, whereas smaller deletions yield efficient network disruption, we conclude that some sequence(s) in the head domain (within residues 31-87) are required for the earliest steps in filament assembly. Insertional mutagenesis in the nonhelical spacer region within the rod domain reveals that as many as eight additional amino acids can be tolerated without disrupting assembly competence.

scholarly journals Vibrational spectroscopic studies of molecular associations by local anesthetics

1980 ◽  
Vol 58 (19) ◽  
pp. 2080-2088 ◽  
Author(s):  
M. Guérin ◽  
J.-M. Dumas ◽  
C. Sandorfy
Keyword(s):  
Local Anesthetics ◽  
Spectroscopic Studies ◽  
Chemical Mechanism ◽  
Molecular Associations ◽  
Text Types ◽  
Infrared Spectroscopic ◽  
Self Association ◽  
Marked Tendency

Infrared spectroscopic studies have been performed on H-bonding for a number of local anesthetics: benzocaine, procaine, tetracaine, lidocaine, dibucaine, and three barbiturates: phenobarbital, pentobarbital, and thiopental. All these compounds have a marked tendency for self-association. When they are put into contact with systems containing H-bonds of the [Formula: see text], [Formula: see text], or [Formula: see text] types, however, the degree of self-association decreases and new H-bonds are formed at the expense of the former. The possible consequences of this for the chemical mechanism of anesthesia are briefly discussed.

scholarly journals Redox-mediated regulation of a labile, evolutionarily conserved cross-β structure formed by the TDP43 low complexity domain

2019 ◽  
Author(s):  
Yi Lin ◽  
Xiaoming Zhou ◽  
Masato Kato ◽  
Daifei Liu ◽  
Sina Ghaemmaghami ◽  
...  
Keyword(s):  
Rna Binding ◽  
Thioredoxin Reductase ◽  
Methionine Sulfoxide ◽  
Low Complexity ◽  
Methionine Sulfoxide Reductase ◽  
Methionine Residue ◽  
Low Concentrations ◽  
Evolutionarily Conserved ◽  
Methionine Residues ◽  
Self Association

SummaryAn evolutionarily conserved low complexity (LC) domain is found within a 152 residue segment localized to the carboxyl-terminal region of the TDP43 RNA-binding protein. This TDP43 LC domain contains ten conserved methionine residues. Self-association of this domain leads to the formation of liquid-like droplets composed of labile, cross-β polymers. Exposure of polymers to low concentrations of H2O2 leads to a phenomenon of droplet melting that can be reversed upon exposure of the oxidized protein to the MsrA and MsrB methionine sulfoxide reductase enzymes, thioredoxin, thioredoxin reductase and NADPH. Morphological features of the cross-β polymers were revealed by a method of H2O2-mediated footprinting. Similar TDP43 LC domain footprints were observed in highly polymerized, hydrogel samples, liquid-like droplet samples, and living cells. The ability of H2O2 to impede cross-β polymerization was abrogated by a prominent ALS-causing mutation that changes methionine residue 337 to valine. These observations offer potentially useful insight into the biological role of TDP43 in facilitating synapse-localized translation, as well as aberrant aggregation of the protein in neurodegenerative disease.

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