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71.
Nuclear pore complexes (NPCs) are built from ~30 different proteins called nucleoporins or Nups. Previous studies have shown that several Nups exhibit cell-type-specific expression and that mutations in NPC components result in tissue-specific diseases. Here we show that a specific change in NPC composition is required for both myogenic and neuronal differentiation. The transmembrane nucleoporin Nup210 is absent in proliferating myoblasts and embryonic stem cells (ESCs) but becomes expressed and incorporated into NPCs during cell differentiation. Preventing Nup210 production by RNAi blocks myogenesis and the differentiation of ESCs into neuroprogenitors. We found that the addition of Nup210 to NPCs does not affect nuclear transport but is required for the induction of genes that are essential for cell differentiation. Our results identify a single change in NPC composition as an essential step in cell differentiation and establish a role for Nup210 in gene expression regulation and cell fate determination. 相似文献
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Molecular Characterization and Identification of Bacillus clausii Strains Marketed for Use in Oral Bacteriotherapy 下载免费PDF全文
Sonia Senesi Francesco Celandroni Arianna Tavanti Emilia Ghelardi 《Applied microbiology》2001,67(2):834-839
A substantial number of Bacillus species have been marketed for use in oral bacteriotherapy because of their purported ability to prevent or treat various gastrointestinal disorders. Recently, some of the Bacillus strains in Enterogermina, which is made up of aqueous suspensions of viable Bacillus spores, have been partially characterized and aligned with members of the Bacillus alcalophilus subgroup rather than with Bacillus subtilis, as previously reported. With a view toward verifying the original taxonomic position of the Enterogermina strains, we catalogued both phenotypic and genotypic traits exhibited by the four Bacillus strains isolated from the spore mixtures found in original commercial preparations dated 1975 and 1984 and commercial preparations now being propagated industrially. Analyses of physiological and biochemical traits, complete 16S rRNA gene sequences, DNA-DNA reassociation, tRNA intergenic spacer length polymorphism, single-strand conformation polymorphism of PCR-amplified spacer regions of tRNA genes, and randomly amplified polymorphic DNA led to the finding that all of the Enterogermina strains belong to a unique genospecies, which is unequivocally identified as the alkalitolerant species Bacillus clausii. Moreover, we provide evidence that in contrast to several reference strains of B. clausii, the strains constituting Enterogermina are characterized by a notable low level of intraspecific genome diversity and that each strain has remained the same for the last 25 years. 相似文献
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Sandro L. Fornili Rita Pizzi Davide Rebeccani 《International journal of peptide research and therapeutics》2010,16(4):223-231
We have investigated structural and dynamic properties of the synthetic peptide hlF1-11 (GRRRSVQWCA, i.e., the first 11 N-terminal
amino acids of the human lactoferrin protein) in water, 250 mM NaCl solution, 50% (V/V) water–trifluoroethanol mixture, and
in the membrane mimetic 4:4:1 methanol–chloroform–water mixture. For comparison, we have also performed analogous simulations
for the biologically inactive control peptide featuring Ala substitutions in the 2, 3, 6 and 9 positions of the hlF1-11 sequence.
Statistical analyses of the trajectories indicate that only in the membrane-mimicking medium hlF1-11 adopts preferentially
a conformation suitable to interact effectively with the membrane. In this conformation the peptide cationic region is rather
flexible and elongated, while the C-terminal hydrophobic moiety appears as a more rigid hairpin-shaped loop approximately
perpendicular to the cationic region. No such conformation is statistically relevant for the control peptide. 相似文献
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Mario Stampanoni Bassi Tommaso Nuzzo Luana Gilio Mattia Miroballo Alessia Casamassa Fabio Buttari Paolo Bellantonio Roberta Fantozzi Giovanni Galifi Roberto Furlan Annamaria Finardi Arianna De Rosa Anna Di Maio Francesco Errico Diego Centonze Alessandro Usiello 《Journal of neurochemistry》2021,159(5):857-866