LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 5 of total 5

Search options

  1. Article ; Online: Transfer of polarity information via diffusion of Wnt ligands in C. elegans embryos.

    Recouvreux, Pierre / Pai, Pritha / Dunsing, Valentin / Torro, Rémy / Ludanyi, Monika / Mélénec, Pauline / Boughzala, Mariem / Bertrand, Vincent / Lenne, Pierre-François

    Current biology : CB

    2024  

    Abstract: Different signaling mechanisms concur to ensure robust tissue patterning and cell fate instruction during animal development. Most of these mechanisms rely on signaling proteins that are produced, transported, and detected. The spatiotemporal dynamics of ...

    Abstract Different signaling mechanisms concur to ensure robust tissue patterning and cell fate instruction during animal development. Most of these mechanisms rely on signaling proteins that are produced, transported, and detected. The spatiotemporal dynamics of signaling molecules are largely unknown, yet they determine signal activity's spatial range and time frame. Here, we use the Caenorhabditis elegans embryo to study how Wnt ligands, an evolutionarily conserved family of signaling proteins, dynamically organize to establish cell polarity in a developing tissue. We identify how Wnt ligands, produced in the posterior half of the embryos, spread extracellularly to transmit information to distant target cells in the anterior half. With quantitative live imaging and fluorescence correlation spectroscopy, we show that Wnt ligands diffuse through the embryo over a timescale shorter than the cell cycle, in the intercellular space, and outside the tissue below the eggshell. We extracted diffusion coefficients of Wnt ligands and their receptor Frizzled and characterized their co-localization. Integrating our different measurements and observations in a simple computational framework, we show how fast diffusion in the embryo can polarize individual cells through a time integration of the arrival of the ligands at the target cells. The polarity established at the tissue level by a posterior Wnt source can be transferred to the cellular level. Our results support a diffusion-based long-range Wnt signaling, which is consistent with the dynamics of developing processes.
    Language English
    Publishing date 2024-04-05
    Publishing country England
    Document type Journal Article
    ZDB-ID 1071731-6
    ISSN 1879-0445 ; 0960-9822
    ISSN (online) 1879-0445
    ISSN 0960-9822
    DOI 10.1016/j.cub.2024.03.030
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 3208: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: The abundant and essential HU proteins in Deinococcus deserti and Deinococcus radiodurans are translated from leaderless mRNA.

    Bouthier de la Tour, Claire / Blanchard, Laurence / Dulermo, Rémi / Ludanyi, Monika / Devigne, Alice / Armengaud, Jean / Sommer, Suzanne / de Groot, Arjan

    Microbiology (Reading, England)

    2015  Volume 161, Issue 12, Page(s) 2410–2422

    Abstract: HU proteins have an important architectural role in nucleoid organization in bacteria. Compared with HU of many bacteria, HU proteins from Deinococcus species possess an N-terminal lysine-rich extension similar to the eukaryotic histone H1 C-terminal ... ...

    Abstract HU proteins have an important architectural role in nucleoid organization in bacteria. Compared with HU of many bacteria, HU proteins from Deinococcus species possess an N-terminal lysine-rich extension similar to the eukaryotic histone H1 C-terminal domain involved in DNA compaction. The single HU gene in Deinococcus radiodurans, encoding DrHU, is required for nucleoid compaction and cell viability. Deinococcus deserti contains three expressed HU genes, encoding DdHU1, DdHU2 and DdHU3. Here, we show that either DdHU1 or DdHU2 is essential in D. deserti. DdHU1 and DdHU2, but not DdHU3, can substitute for DrHU in D. radiodurans, indicating that DdHU3 may have a non-essential function different from DdHU1, DdHU2 and DrHU. Interestingly, the highly abundant DrHU and DdHU1 proteins, and also the less expressed DdHU2, are translated in Deinococcus from leaderless mRNAs, which lack a 5'-untranslated region and, hence, the Shine-Dalgarno sequence. Unexpectedly, cloning the DrHU or DdHU1 gene under control of a strong promoter in an expression plasmid, which results in leadered transcripts, strongly reduced the DrHU and DdHU1 protein level in D. radiodurans compared with that obtained from the natural leaderless gene. We also show that the start codon position for DrHU and DdHU1 should be reannotated, resulting in proteins that are 15 and 4 aa residues shorter than initially reported. The expression level and start codon correction were crucial for functional characterization of HU in Deinococcus.
    MeSH term(s) 5' Untranslated Regions ; Amino Acid Sequence ; Bacterial Proteins/chemistry ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Codon, Initiator/genetics ; Codon, Initiator/metabolism ; DNA-Binding Proteins/chemistry ; DNA-Binding Proteins/genetics ; DNA-Binding Proteins/metabolism ; Deinococcus/chemistry ; Deinococcus/genetics ; Deinococcus/metabolism ; Gene Expression Regulation, Bacterial ; Molecular Sequence Data ; Protein Biosynthesis ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; Sequence Alignment
    Chemical Substances 5' Untranslated Regions ; Bacterial Proteins ; Codon, Initiator ; DNA-Binding Proteins ; RNA, Messenger ; histone-like protein HU, bacteria
    Language English
    Publishing date 2015-09-18
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1180712-x
    ISSN 1465-2080 ; 1350-0872
    ISSN (online) 1465-2080
    ISSN 1350-0872
    DOI 10.1099/mic.0.000186
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Ud II Zs.140: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article ; Online: A Cyclin T1 point mutation that abolishes positive transcription elongation factor (P-TEFb) binding to Hexim1 and HIV tat.

    Verstraete, Nina / Kuzmina, Alona / Diribarne, Gaelle / Nguyen, Van Trung / Kobbi, Lydia / Ludanyi, Monika / Taube, Ran / Bensaude, Olivier

    Retrovirology

    2014  Volume 11, Page(s) 50

    Abstract: Background: The positive transcription elongation factor b (P-TEFb) plays an essential role in activating HIV genome transcription. It is recruited to the HIV LTR promoter through an interaction between the Tat viral protein and its Cyclin T1 subunit. P- ...

    Abstract Background: The positive transcription elongation factor b (P-TEFb) plays an essential role in activating HIV genome transcription. It is recruited to the HIV LTR promoter through an interaction between the Tat viral protein and its Cyclin T1 subunit. P-TEFb activity is inhibited by direct binding of its subunit Cyclin T (1 or 2) with Hexim (1 or 2), a cellular protein, bound to the 7SK small nuclear RNA. Hexim1 competes with Tat for P-TEFb binding.
    Results: Mutations that impair human Cyclin T1/Hexim1 interaction were searched using systematic mutagenesis of these proteins coupled with a yeast two-hybrid screen for loss of protein interaction. Evolutionary conserved Hexim1 residues belonging to an unstructured peptide located N-terminal of the dimerization domain, were found to be critical for P-TEFb binding. Random mutagenesis of the N-terminal region of Cyclin T1 provided identification of single amino-acid mutations that impair Hexim1 binding in human cells. Furthermore, conservation of critical residues supported the existence of a functional Hexim1 homologue in nematodes.
    Conclusions: Single Cyclin T1 amino-acid mutations that impair Hexim1 binding are located on a groove between the two cyclin folds and define a surface overlapping the HIV-1 Tat protein binding surface. One residue, Y175, in the centre of this groove was identified as essential for both Hexim1 and Tat binding to P-TEFb as well as for HIV transcription.
    MeSH term(s) Cyclin T/chemistry ; Cyclin T/metabolism ; Humans ; Hydrogen Bonding ; Point Mutation ; Positive Transcriptional Elongation Factor B/metabolism ; Protein Folding ; RNA-Binding Proteins/metabolism ; Structure-Activity Relationship ; Transcription Factors ; Two-Hybrid System Techniques ; tat Gene Products, Human Immunodeficiency Virus/metabolism
    Chemical Substances CCNT1 protein, human ; Cyclin T ; HEXIM1 protein, human ; RNA-Binding Proteins ; Transcription Factors ; tat Gene Products, Human Immunodeficiency Virus ; Positive Transcriptional Elongation Factor B (EC 2.7.11.-)
    Language English
    Publishing date 2014-07-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1742-4690
    ISSN (online) 1742-4690
    DOI 10.1186/1742-4690-11-50
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Article ; Online: RNA sequencing and proteogenomics reveal the importance of leaderless mRNAs in the radiation-tolerant bacterium Deinococcus deserti.

    de Groot, Arjan / Roche, David / Fernandez, Bernard / Ludanyi, Monika / Cruveiller, Stéphane / Pignol, David / Vallenet, David / Armengaud, Jean / Blanchard, Laurence

    Genome biology and evolution

    2014  Volume 6, Issue 4, Page(s) 932–948

    Abstract: Deinococcus deserti is a desiccation- and radiation-tolerant desert bacterium. Differential RNA sequencing (RNA-seq) was performed to explore the specificities of its transcriptome. Strikingly, for 1,174 (60%) mRNAs, the transcription start site was ... ...

    Abstract Deinococcus deserti is a desiccation- and radiation-tolerant desert bacterium. Differential RNA sequencing (RNA-seq) was performed to explore the specificities of its transcriptome. Strikingly, for 1,174 (60%) mRNAs, the transcription start site was found exactly at (916 cases, 47%) or very close to the translation initiation codon AUG or GUG. Such proportion of leaderless mRNAs, which may resemble ancestral mRNAs, is unprecedented for a bacterial species. Proteomics showed that leaderless mRNAs are efficiently translated in D. deserti. Interestingly, we also found 173 additional transcripts with a 5'-AUG or 5'-GUG that would make them competent for ribosome binding and translation into novel small polypeptides. Fourteen of these are predicted to be leader peptides involved in transcription attenuation. Another 30 correlated with new gene predictions and/or showed conservation with annotated and nonannotated genes in other Deinococcus species, and five of these novel polypeptides were indeed detected by mass spectrometry. The data also allowed reannotation of the start codon position of 257 genes, including several DNA repair genes. Moreover, several novel highly radiation-induced genes were found, and their potential roles are discussed. On the basis of our RNA-seq and proteogenomics data, we propose that translation of many of the novel leaderless transcripts, which may have resulted from single-nucleotide changes and maintained by selective pressure, provides a new explanation for the generation of a cellular pool of small peptides important for protection of proteins against oxidation and thus for radiation/desiccation tolerance and adaptation to harsh environmental conditions.
    MeSH term(s) Adaptation, Physiological/genetics ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Base Sequence ; Deinococcus/physiology ; Evolution, Molecular ; Molecular Sequence Data ; Proteomics ; RNA, Bacterial/genetics ; RNA, Bacterial/metabolism ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; Radiation Tolerance/physiology ; Sequence Analysis, RNA
    Chemical Substances Bacterial Proteins ; RNA, Bacterial ; RNA, Messenger
    Language English
    Publishing date 2014-04-10
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2495328-3
    ISSN 1759-6653 ; 1759-6653
    ISSN (online) 1759-6653
    ISSN 1759-6653
    DOI 10.1093/gbe/evu069
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article ; Online: Radiation response in Deinococcus deserti: IrrE is a metalloprotease that cleaves repressor protein DdrO.

    Ludanyi, Monika / Blanchard, Laurence / Dulermo, Rémi / Brandelet, Géraldine / Bellanger, Laurent / Pignol, David / Lemaire, David / de Groot, Arjan

    Molecular microbiology

    2014  Volume 94, Issue 2, Page(s) 434–449

    Abstract: Deinococcus bacteria are famous for their extreme radiation tolerance. The IrrE protein was shown to be essential for radiation tolerance and, in an unelucidated manner, for induction of a number of genes in response to radiation, including recA and ... ...

    Abstract Deinococcus bacteria are famous for their extreme radiation tolerance. The IrrE protein was shown to be essential for radiation tolerance and, in an unelucidated manner, for induction of a number of genes in response to radiation, including recA and other DNA repair genes. Earlier studies indicated that IrrE could be a zinc peptidase, but proteolytic activity was not demonstrated. Here, using several in vivo and in vitro experiments, IrrE from Deinococcus deserti was found to interact with DdrO, a predicted regulator encoded by a radiation-induced gene that is, like irrE, highly conserved in Deinococcus. Moreover, IrrE was found to cleave DdrO in vitro and when the proteins were coexpressed in Escherichia coli. This cleavage was not observed in the presence of metal chelator EDTA or when IrrE contains a mutation in the conserved active-site motif of metallopeptidases. In D. deserti, IrrE-dependent cleavage of DdrO was observed after exposure to radiation. Furthermore, DdrO-dependent repression of the promoter of a radiation-induced gene was shown. These results demonstrate that IrrE is a metalloprotease and we propose that IrrE-mediated cleavage inactivates repressor protein DdrO, leading to transcriptional induction of various genes required for repair and survival after exposure of Deinococcus to radiation.
    MeSH term(s) Amino Acid Sequence ; Deinococcus/radiation effects ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Gene Expression ; Gene Expression Regulation, Bacterial ; Metalloproteases/metabolism ; Molecular Sequence Data ; Proteolysis ; Repressor Proteins/metabolism ; Sequence Alignment ; Stress, Physiological
    Chemical Substances Repressor Proteins ; Metalloproteases (EC 3.4.-)
    Language English
    Publishing date 2014-10
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 619315-8
    ISSN 1365-2958 ; 0950-382X
    ISSN (online) 1365-2958
    ISSN 0950-382X
    DOI 10.1111/mmi.12774
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 2502: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top