Huntingtonova choroba (HD) je autozomálně dominantní neurodegenerativní onemocnění způsobené zvýšením počtu polyglutaminových repetic (> 35 repetic) v genu pro protein huntingtin. HD je charakteristická pomalými progresivními změnami pohybového aparátu a osobnosti, kdy tyto změny jsou často doprovázeny ztrátou tělesné hmotnosti. Do dnešního dne není znám přesný mechanizmus patofyziologie choroby. Poruchy pohybových funkcí reflektují masivní poškození specifických částí mozku (striatum), které bylo popsáno u pacientů s HD. V roce 2013 Sbodio et al [1] popsali zvýšené množství proteinu Acyl‑CoA binding domain containing 3 (ACBD3) ve striatu HD pacientů. Protein ACBD3 hraje nezastupitelnou roli v mnoha buněčných procesech, a to především díky interakci s různými vazebnými partnery. ACBD3 je esenciální při neuronálním dělení, neurodegeneraci, udržení lipidové homeostáze, stresové odpovědi, virové replikaci, apoptóze, udržení struktury golgiho komplexu. V této práci jsme prokázali nepřítomnost proteinu ACBD3 v mitochondriích v lidských kožních fibroblastech a navíc jsme potvrdili, že změny celkové hladiny proteinu ACBD3 ve fibroblastech HD pacientů nejsou konzistentní.

Huntington's disease (HD) is an autosomal‑dominant neurodegenerative disease caused by the expansion of polyglutamine repeats (> 35 repeats) in the nuclear gene for the huntingtin protein. HD is characterized by slow progressive changes in motor behaviour and personality that are sometimes accompanied by weight loss. To date, the exact mechanisms of HD pathophysiology have not been defined. Impaired motor behaviour reflecting massive and selective destruction of the striatum has been observed in patients with HD. Sbodio et al. [1] reported in 2013 that Acyl‑CoA binding domain containing 3 (ACBD3) protein levels were elevated in the striatum of HD patients and connected with higher neurotoxicity in HD. The ACBD3 protein plays essential roles in many different cellular functions via interactions with a multitude of partners. ACBD3 is involved in neuronal stem cell self‑renewal, neurodegeneration, lipid homeostasis, stress resistance, intracellular vesicle trafficking, organelle maintenance, viral replication and the apoptotic response. Herein, we found that ACBD3 in not present in the mitochondria in skin fibroblasts. Moreover, our findings also revealed that the total cellular level of ACBD3 is not consistent among the fibroblasts of HD patients.

• Klíčová slova
• lidské kožní fibroblasty, Acyl-CoA binding domain containing 3 protein,
• MeSH
• adaptorové proteiny signální transdukční * fyziologie   metabolismus   MeSH
• buněčné linie metabolismus   MeSH
• dospělí MeSH
• fibroblasty metabolismus   MeSH
• frakcionace buněk MeSH
• heterozygot MeSH
• Huntingtonova nemoc * metabolismus   MeSH
• imunohistochemie MeSH
• kůže * metabolismus   patologie   MeSH
• lidé MeSH
• membránové proteiny * fyziologie   metabolismus   MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

• MeSH
• apolipoproteiny B analýza   genetika   metabolismus   MeSH
• cholesterol fyziologie   MeSH
• koronární nemoc genetika   metabolismus   MeSH
• molekulární biologie MeSH
• mutace MeSH
• polymorfismus genetický MeSH
• vazebná místa genetika   MeSH
• Publikační typ
• přehledy MeSH

The HMG-box domain of approximately 75 amino acid residues was originally identified as the domain that mediates the DNA-binding of chromatin-associated high-mobility group (HMG) proteins of the HMGB type. In the last few years, HMG-box domains have been found in various DNA-binding proteins including transcription factors and subunits of chromatin-remodeling complexes. HMG-box domains mediate either non-sequence-specific (e.g., HMGB-type proteins) or sequence-specific (e.g., transcription factors) DNA binding. Both types of HMG-box domains bind non-B-type DNA structures (bent, kinked and unwound) with high affinity. In addition, HMG-box domains are involved in a variety of protein-protein interactions. Here, we have examined the human and plant genomes for genes encoding HMG-box domains. Compared to plants, human cells contain a larger variety of HMG-box proteins. Whereas in humans transcription factors are the most divergent group of HMG-box proteins, in plants the chromosomal HMGB-type proteins are most variable.

• MeSH
• DNA vazebné proteiny MeSH
• domény HMG-Box MeSH
• financování organizované MeSH
• genom lidský MeSH
• genom rostlinný MeSH
• jaderné proteiny MeSH
• lidé MeSH
• proteiny Drosophily MeSH
• proteiny HMGB MeSH
• restrukturace chromatinu MeSH
• transkripční faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

Histone deacetylase 6 (HDAC6) is a multidomain cytosolic enzyme having tubulin deacetylase activity that has been unequivocally assigned to the second of the tandem catalytic domains. However, virtually no information exists on the contribution of other HDAC6 domains on tubulin recognition. Here, using recombinant protein expression, site-directed mutagenesis, fluorimetric and biochemical assays, microscale thermophoresis, and total internal reflection fluorescence microscopy, we identified the N-terminal, disordered region of HDAC6 as a microtubule-binding domain and functionally characterized it to the single-molecule level. We show that the microtubule-binding motif spans two positively charged patches comprising residues Lys-32 to Lys-58. We found that HDAC6-microtubule interactions are entirely independent of the catalytic domains and are mediated by ionic interactions with the negatively charged microtubule surface. Importantly, a crosstalk between the microtubule-binding domain and the deacetylase domain was critical for recognition and efficient deacetylation of free tubulin dimers both in vitro and in vivo Overall, our results reveal that recognition of substrates by HDAC6 is more complex than previously appreciated and that domains outside the tandem catalytic core are essential for proficient substrate deacetylation.

• MeSH
• acetylace MeSH
• histondeacetylasa 6 metabolismus   MeSH
• katalytická doména MeSH
• lidé MeSH
• mikrotubuly metabolismus   MeSH
• proteinové domény fyziologie   MeSH
• sekvence aminokyselin MeSH
• substrátová specifita MeSH
• tubulin metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The spontaneous host-range mutants 812F1 and K1/420 are derived from polyvalent phage 812 that is almost identical to phage K, belonging to family Myoviridae and genus Kayvirus. Phage K1/420 is used for the phage therapy of staphylococcal infections. Endolysin of these mutants designated LysF1, consisting of an N-terminal cysteine-histidine-dependent aminohydrolase/peptidase (CHAP) domain and C-terminal SH3b cell wall-binding domain, has deleted middle amidase domain compared to wild-type endolysin. In this work, LysF1 and both its domains were prepared as recombinant proteins and their function was analyzed. LysF1 had an antimicrobial effect on 31 Staphylococcus species of the 43 tested. SH3b domain influenced antimicrobial activity of LysF1, since the lytic activity of the truncated variant containing the CHAP domain alone was decreased. The results of a co-sedimentation assay of SH3b domain showed that it was able to bind to three types of purified staphylococcal peptidoglycan 11.2, 11.3, and 11.8 that differ in their peptide bridge, but also to the peptidoglycan type 11.5 of Streptococcus uberis, and this capability was verified in vivo using the fusion protein with GFP and fluorescence microscopy. Using several different approaches, including NMR, we have not confirmed the previously proposed interaction of the SH3b domain with the pentaglycine bridge in the bacterial cell wall. The new naturally raised deletion mutant endolysin LysF1 is smaller than LysK, has a broad lytic spectrum, and therefore is an appropriate enzyme for practical use. The binding spectrum of SH3b domain covering all known staphylococcal peptidoglycan types is a promising feature for creating new chimeolysins by combining it with more effective catalytic domains.

• MeSH
• endopeptidasy genetika   izolace a purifikace   metabolismus   MeSH
• hostitelská specificita * MeSH
• mutantní proteiny genetika   izolace a purifikace   metabolismus   MeSH
• Myoviridae enzymologie   genetika   fyziologie   MeSH
• peptidoglykan metabolismus   MeSH
• proteinové domény MeSH
• sekvenční delece * MeSH
• Staphylococcus virologie   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH

The Orange Carotenoid Protein (OCP) is a water-soluble protein that governs photoprotection in many cyanobacteria. The 35 kDa OCP is structurally and functionally modular, consisting of an N-terminal effector domain (NTD) and a C-terminal regulatory domain (CTD); a carotenoid spans the two domains. The CTD is a member of the ubiquitous Nuclear Transport Factor-2 (NTF2) superfamily (pfam02136). With the increasing availability of cyanobacterial genomes, bioinformatic analysis has revealed the existence of a new family of proteins, homologs to the CTD, the C-terminal domain-like carotenoid proteins (CCPs). Here we purify holo-CCP2 directly from cyanobacteria and establish that it natively binds canthaxanthin (CAN). We use small-angle X-ray scattering (SAXS) to characterize the structure of this carotenoprotein in two distinct oligomeric states. A single carotenoid molecule spans the two CCPs in the dimer. Our analysis with X-ray footprinting-mass spectrometry (XFMS) identifies critical residues for carotenoid binding that likely contribute to the extreme red shift (ca. 80 nm) of the absorption maximum of the carotenoid bound by the CCP2 dimer and a further 10 nm shift in the tetramer form. These data provide the first structural description of carotenoid binding by a protein consisting of only an NTF2 domain.

• MeSH
• bakteriální proteiny chemie   ultrastruktura   MeSH
• kanthaxanthin chemie   MeSH
• krystalografie rentgenová MeSH
• maloúhlový rozptyl MeSH
• nukleocytoplazmatické transportní proteiny chemie   genetika   ultrastruktura   MeSH
• proteinové domény genetika   MeSH
• sinice chemie   ultrastruktura   MeSH
• vazba proteinů účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Interaction of orthosteric ligands with extracellular domain was described at several aminergic G protein-coupled receptors, including muscarinic acetylcholine receptors. The orthosteric antagonists quinuclidinyl benzilate (QNB) and N-methylscopolamine (NMS) bind to the binding pocket of the muscarinic acetylcholine receptor formed by transmembrane α-helices. We show that high concentrations of either QNB or NMS slow down dissociation of their radiolabeled species from all five subtypes of muscarinic acetylcholine receptors, suggesting allosteric binding. The affinity of NMS at the allosteric site is in the micromolar range for all receptor subtypes. Using molecular modelling of the M2 receptor we found that E172 and E175 in the second extracellular loop and N419 in the third extracellular loop are involved in allosteric binding of NMS. Mutation of these amino acids to alanine decreased affinity of NMS for the allosteric binding site confirming results of molecular modelling. The allosteric binding site of NMS overlaps with the binding site of some allosteric, ectopic and bitopic ligands. Understanding of interactions of NMS at the allosteric binding site is essential for correct analysis of binding and action of these ligands.

• MeSH
• biologické modely MeSH
• CHO buňky MeSH
• Cricetulus MeSH
• kinetika MeSH
• křečci praví MeSH
• lidé MeSH
• ligandy MeSH
• mutantní proteiny chemie   metabolismus   MeSH
• N-methylskopolamin chemie   metabolismus   MeSH
• proteinové domény MeSH
• receptory muskarinové chemie   metabolismus   MeSH
• sekundární struktura proteinů MeSH
• simulace molekulární dynamiky MeSH
• tritium metabolismus   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• zrychlení MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: The Nse1, Nse3 and Nse4 proteins form a tight sub-complex of the large SMC5-6 protein complex. hNSE3/MAGEG1, the mammalian ortholog of Nse3, is the founding member of the MAGE (melanoma-associated antigen) protein family and the Nse4 kleisin subunit is related to the EID (E1A-like inhibitor of differentiation) family of proteins. We have recently shown that human MAGE proteins can interact with NSE4/EID proteins through their characteristic conserved hydrophobic pocket. METHODOLOGY/PRINCIPAL FINDINGS: Using mutagenesis and protein-protein interaction analyses, we have identified a new Nse3/MAGE-binding domain (NMBD) of the Nse4/EID proteins. This short domain is located next to the Nse4 N-terminal kleisin motif and is conserved in all NSE4/EID proteins. The central amino acid residues of the human NSE4b/EID3 domain were essential for its binding to hNSE3/MAGEG1 in yeast two-hybrid assays suggesting they form the core of the binding domain. PEPSCAN ELISA measurements of the MAGEC2 binding affinity to EID2 mutant peptides showed that similar core residues contribute to the EID2-MAGEC2 interaction. In addition, the N-terminal extension of the EID2 binding domain took part in the EID2-MAGEC2 interaction. Finally, docking and molecular dynamic simulations enabled us to generate a structure model for EID2-MAGEC2. Combination of our experimental data and the structure modeling showed how the core helical region of the NSE4/EID domain binds into the conserved pocket characteristic of the MAGE protein family. CONCLUSIONS/SIGNIFICANCE: We have identified a new Nse4/EID conserved domain and characterized its binding to Nse3/MAGE proteins. The conservation and binding of the interacting surfaces suggest tight co-evolution of both Nse4/EID and Nse3/MAGE protein families.

• MeSH
• interakční proteinové domény a motivy MeSH
• intracelulární signální peptidy a proteiny chemie   genetika   metabolismus   MeSH
• jaderné proteiny chemie   MeSH
• konzervovaná sekvence MeSH
• lidé MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• mutageneze cílená MeSH
• peptidové fragmenty chemie   genetika   metabolismus   MeSH
• počítačová simulace MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• Schizosaccharomyces pombe - proteiny chemie   MeSH
• Schizosaccharomyces MeSH
• sekvence aminokyselin MeSH
• substituce aminokyselin MeSH
• techniky dvojhybridového systému MeSH
• transportní proteiny chemie   genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nucleolin is a multifunctional RNA Binding Protein (RBP) with diverse subcellular localizations, including the nucleolus in all eukaryotic cells, the plasma membrane in tumor cells, and the axon in neurons. Here we show that the glycine arginine rich (GAR) domain of nucleolin drives subcellular localization via protein-protein interactions with a kinesin light chain. In addition, GAR sequences mediate plasma membrane interactions of nucleolin. Both these modalities are in addition to the already reported involvement of the GAR domain in liquid-liquid phase separation in the nucleolus. Nucleolin transport to axons requires the GAR domain, and heterozygous GAR deletion mice reveal reduced axonal localization of nucleolin cargo mRNAs and enhanced sensory neuron growth. Thus, the GAR domain governs axonal transport of a growth controlling RNA-RBP complex in neurons, and is a versatile localization determinant for different subcellular compartments. Localization determination by GAR domains may explain why GAR mutants in diverse RBPs are associated with neurodegenerative disease.

• MeSH
• axonální transport genetika   MeSH
• buněčné jadérko metabolismus   ultrastruktura   MeSH
• exprese genu MeSH
• fosfoproteiny chemie   genetika   metabolismus   MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• kineziny genetika   metabolismus   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mutace MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nervus ischiadicus cytologie   metabolismus   MeSH
• neurony cytologie   metabolismus   MeSH
• primární buněčná kultura MeSH
• proteinové domény MeSH
• proteiny vázající RNA chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• spinální ganglia cytologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Isoforms of microtubule-associated protein 2 (MAP2) differ from their homolog Tau in the sequence and interactions of the N-terminal region. Binding of the N-terminal region of MAP2c (N-MAP2c) to the dimerization/docking domains of the regulatory subunit RIIα of cAMP-dependent protein kinase (RIIDD2) and to the Src-homology domain 2 (SH2) of growth factor receptor-bound protein 2 (Grb2) have been described long time ago. However, the structural features of the complexes remained unknown due to the disordered nature of MAP2. Here, we provide structural description of the complexes. We have solved solution structure of N-MAP2c in complex with RIIDD2, confirming formation of an amphiphilic α-helix of MAP2c upon binding, defining orientation of the α-helix in the complex and showing that its binding register differs from previous predictions. Using chemical shift mapping, we characterized the binding interface of SH2-Grb2 and rat MAP2c phosphorylated by the tyrosine kinase Fyn in their complex and proposed a model explaining differences between SH2-Grb2 complexes with rat MAP2c and phosphopeptides with a Grb2-specific sequence. The results provide the structural basis of a potential role of MAP2 in regulating cAMP-dependent phosphorylation cascade via interactions with RIIDD2 and Ras signaling pathway via interactions with SH2-Grb2.

• MeSH
• adaptorový protein Grb2 * metabolismus   chemie   MeSH
• lidé MeSH
• proteinové domény MeSH
• proteiny asociované s mikrotubuly * metabolismus   chemie   genetika   MeSH
• protoonkogenní proteiny c-fyn metabolismus   chemie   genetika   MeSH
• signální transdukce MeSH
• src homologní domény MeSH
• vazba proteinů * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH