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  1. Book ; Online: Meiosis

    Bernstein, Carol / Bernstein, Carol / Bernstein, Harris

    2013  

    Keywords Medical genetics
    Size 1 electronic resource (134 pages)
    Publisher IntechOpen
    Document type Book ; Online
    Note English ; Open Access
    HBZ-ID HT021045058
    ISBN 9789535153856 ; 9535153854
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  2. Article ; Online: Molecular Machines that Facilitate Bacterial Outer Membrane Protein Biogenesis.

    Doyle, Matthew Thomas / Bernstein, Harris D

    Annual review of biochemistry

    2024  

    Abstract: Almost all outer membrane proteins (OMPs) in Gram-negative bacteria contain a β-barrel domain that spans the outer membrane (OM). To reach the OM, OMPs must be translocated across the inner membrane by the Sec machinery, transported across the crowded ... ...

    Abstract Almost all outer membrane proteins (OMPs) in Gram-negative bacteria contain a β-barrel domain that spans the outer membrane (OM). To reach the OM, OMPs must be translocated across the inner membrane by the Sec machinery, transported across the crowded periplasmic space through the assistance of molecular chaperones, and finally assembled (folded and inserted into the OM) by the β-barrel assembly machine. In this review, we discuss how considerable new insights into the contributions of these factors to OMP biogenesis have emerged in recent years through the development of novel experimental, computational, and predictive methods. In addition, we describe recent evidence that molecular machines that were thought to function independently might interact to form dynamic intermembrane supercomplexes. Finally, we discuss new results that suggest that OMPs are inserted primarily near the middle of the cell and packed into supramolecular structures (OMP islands) that are distributed throughout the OM.
    Language English
    Publishing date 2024-04-11
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 207924-0
    ISSN 1545-4509 ; 0066-4154
    ISSN (online) 1545-4509
    ISSN 0066-4154
    DOI 10.1146/annurev-biochem-030122-033754
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Bile acids as carcinogens in the colon and at other sites in the gastrointestinal system.

    Bernstein, Harris / Bernstein, Carol

    Experimental biology and medicine (Maywood, N.J.)

    2022  Volume 248, Issue 1, Page(s) 79–89

    Abstract: Colon cancer incidence is associated with a high-fat diet. Such a diet is linked to elevated levels of bile acids in the gastrointestinal system and the circulation. Secondary bile acids are produced by microorganisms present at high concentrations in ... ...

    Abstract Colon cancer incidence is associated with a high-fat diet. Such a diet is linked to elevated levels of bile acids in the gastrointestinal system and the circulation. Secondary bile acids are produced by microorganisms present at high concentrations in the colon. Recent prospective studies and a retrospective study in humans associate high circulating blood levels of secondary bile acids with increased risk of colon cancer. Feeding mice a diet containing a secondary bile acid, so their feces have the bile acid at a level comparable to that in the feces of humans on a high-fat diet, also causes colon cancer in the mice. Studies using human cells grown in culture illuminate some mechanisms by which bile acids cause cancer. In human cells, bile acids cause oxidative stress leading to oxidative DNA damage. Increased DNA damage increases the occurrence of mutations and epimutations, some of which provide a cellular growth advantage such as apoptosis resistance. Cells with such mutations/epimutations increase by natural selection. Apoptosis, or programmed cell death, is a beneficial process that eliminates cells with unrepaired DNA damage, whereas apoptosis-resistant cells are able to survive DNA damage using inaccurate repair processes. This results in apoptosis-resistant cells having more frequent mutations/epimutations, some of which are carcinogenic. The experiments on cultured human cells have provided a basis for understanding at the molecular level the human studies that recently reported an association of bile acids with colon cancer, and the mouse studies showing directly that bile acids cause colon cancer. Similar, but more limited, findings of an association of dietary bile acids with other cancers of the gastrointestinal system suggest that understanding the role of bile acids in colon carcinogenesis may contribute to understanding carcinogenesis in other organs.
    MeSH term(s) Humans ; Mice ; Animals ; Bile Acids and Salts ; Carcinogens ; Retrospective Studies ; Colonic Neoplasms/metabolism ; Carcinogenesis
    Chemical Substances Bile Acids and Salts ; Carcinogens
    Language English
    Publishing date 2022-11-19
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 4015-0
    ISSN 1535-3699 ; 1525-1373 ; 0037-9727
    ISSN (online) 1535-3699 ; 1525-1373
    ISSN 0037-9727
    DOI 10.1177/15353702221131858
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: The patatin-like protein PlpD forms novel structurally dynamic homodimers in the

    Hanson, Sarah E / Doyle, Matthew Thomas / Bernstein, Harris D

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Members of the Omp85 superfamily of outer membrane proteins (OMPs) found in Gram-negative bacteria, mitochondria and chloroplasts are characterized by a distinctive 16-stranded β-barrel transmembrane domain and at least one periplasmic POTRA domain. All ... ...

    Abstract Members of the Omp85 superfamily of outer membrane proteins (OMPs) found in Gram-negative bacteria, mitochondria and chloroplasts are characterized by a distinctive 16-stranded β-barrel transmembrane domain and at least one periplasmic POTRA domain. All previously studied Omp85 proteins promote critical OMP assembly and/or protein translocation reactions.
    Language English
    Publishing date 2023-04-17
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.04.17.537245
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Function of the Omp85 Superfamily of Outer Membrane Protein Assembly Factors and Polypeptide Transporters.

    Doyle, Matthew Thomas / Bernstein, Harris D

    Annual review of microbiology

    2022  Volume 76, Page(s) 259–279

    Abstract: The Omp85 protein superfamily is found in the outer membrane (OM) of all gram-negative bacteria and eukaryotic organelles of bacterial origin. Members of the family catalyze both the membrane insertion of β-barrel proteins and the translocation of ... ...

    Abstract The Omp85 protein superfamily is found in the outer membrane (OM) of all gram-negative bacteria and eukaryotic organelles of bacterial origin. Members of the family catalyze both the membrane insertion of β-barrel proteins and the translocation of proteins across the OM. Although the mechanism(s) by which these proteins function is unclear, striking new insights have emerged from recent biochemical and structural studies. In this review we discuss the entire Omp85 superfamily but focus on the function of the best-studied member, BamA, which is an essential and highly conserved component of the bacterial barrel assembly machinery (BAM). Because BamA has multiple functions that overlap with those of other Omp85 proteins, it is likely the prototypical member of the Omp85 superfamily. Furthermore, BamA has become a protein of great interest because of the recent discovery of small-molecule inhibitors that potentially represent an important new class of antibiotics.
    MeSH term(s) Bacterial Outer Membrane Proteins/genetics ; Bacterial Outer Membrane Proteins/metabolism ; Escherichia coli Proteins/metabolism ; Membrane Transport Proteins/genetics ; Peptides/metabolism ; Protein Folding
    Chemical Substances Bacterial Outer Membrane Proteins ; Escherichia coli Proteins ; Membrane Transport Proteins ; Peptides
    Language English
    Publishing date 2022-06-01
    Publishing country United States
    Document type Journal Article ; Review ; Research Support, N.I.H., Intramural
    ZDB-ID 207931-8
    ISSN 1545-3251 ; 0066-4227
    ISSN (online) 1545-3251
    ISSN 0066-4227
    DOI 10.1146/annurev-micro-033021-023719
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The Escherichia coli outer membrane protein OmpA acquires secondary structure prior to its integration into the membrane.

    Wang, Xu / Bernstein, Harris D

    The Journal of biological chemistry

    2022  Volume 298, Issue 4, Page(s) 101802

    Abstract: Almost all proteins that reside in the outer membrane (OM) of Gram-negative bacteria contain a membrane-spanning segment that folds into a unique β barrel structure and inserts into the membrane by an unknown mechanism. To obtain further insight into ... ...

    Abstract Almost all proteins that reside in the outer membrane (OM) of Gram-negative bacteria contain a membrane-spanning segment that folds into a unique β barrel structure and inserts into the membrane by an unknown mechanism. To obtain further insight into outer membrane protein (OMP) biogenesis, we revisited the surprising observation reported over 20 years ago that the Escherichia coli OmpA β barrel can be assembled into a native structure in vivo when it is expressed as two noncovalently linked fragments. Here, we show that disulfide bonds between β strand 4 in the N-terminal fragment and β strand 5 in the C-terminal fragment can form in the periplasmic space and greatly increase the efficiency of assembly of "split" OmpA, but only if the cysteine residues are engineered in perfect register (i.e., they are aligned in the fully folded β barrel). In contrast, we observed only weak disulfide bonding between β strand 1 in the N-terminal fragment and β strand 8 in the C-terminal fragment that would form a closed or circularly permutated β barrel. Our results not only demonstrate that β barrels begin to fold into a β-sheet-like structure before they are integrated into the OM but also help to discriminate among the different models of OMP biogenesis that have been proposed.
    MeSH term(s) Bacterial Outer Membrane Proteins/chemical synthesis ; Bacterial Outer Membrane Proteins/metabolism ; Cell Membrane/metabolism ; Disulfides/metabolism ; Escherichia coli/metabolism ; Protein Conformation, beta-Strand ; Protein Folding ; Protein Structure, Secondary
    Chemical Substances Bacterial Outer Membrane Proteins ; Disulfides ; OMPA outer membrane proteins (149024-69-1)
    Language English
    Publishing date 2022-03-04
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1016/j.jbc.2022.101802
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Type V Secretion in Gram-Negative Bacteria.

    Bernstein, Harris D

    EcoSal Plus

    2019  Volume 8, Issue 2

    Abstract: Type V, or "autotransporter," secretion is a term used to refer to several simple protein export pathways that are found in a wide range of Gram-negative bacteria. Autotransporters are generally single polypeptides that consist of an extracellular (" ... ...

    Abstract Type V, or "autotransporter," secretion is a term used to refer to several simple protein export pathways that are found in a wide range of Gram-negative bacteria. Autotransporters are generally single polypeptides that consist of an extracellular ("passenger") domain and a β barrel domain that anchors the protein to the outer membrane (OM). Although it was originally proposed that the passenger domain is secreted through a channel formed solely by the covalently linked β barrel domain, experiments performed primarily on the type Va, or "classical," autotransporter pathway have challenged this hypothesis. Several lines of evidence strongly suggest that both the secretion of the passenger domain and the membrane integration of the β barrel domain are catalyzed by the barrel assembly machinery (Bam) complex, a conserved hetero-oligomer that plays an essential role in the assembly of most integral OM proteins. The secretion reaction appears to be driven at least in part by the folding of the passenger domain in the extracellular space. Although many aspects of autotransporter biogenesis remain to be elucidated, it will be especially interesting to determine whether the different classes of proteins that fall under the type V rubric-most of which have not been examined in detail-are assembled by the same basic mechanism as classical autotransporters.
    MeSH term(s) Bacterial Outer Membrane Proteins/metabolism ; Escherichia coli/metabolism ; Escherichia coli Proteins/metabolism ; Gram-Negative Bacteria/metabolism ; Models, Molecular ; Protein Folding ; Protein Structure, Tertiary ; Protein Transport ; Type V Secretion Systems/metabolism
    Chemical Substances Bacterial Outer Membrane Proteins ; Escherichia coli Proteins ; Type V Secretion Systems
    Language English
    Publishing date 2019-03-06
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Intramural
    ISSN 2324-6200
    ISSN (online) 2324-6200
    DOI 10.1128/ecosalplus.ESP-0031-2018
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Small Molecule Antibiotics Inhibit Distinct Stages of Bacterial Outer Membrane Protein Assembly.

    Peterson, Janine H / Doyle, Matthew Thomas / Bernstein, Harris D

    mBio

    2022  Volume 13, Issue 5, Page(s) e0228622

    Abstract: Several antibacterial compounds have recently been discovered that potentially inhibit the activity of BamA, an essential subunit of a heterooligomer ( ... ...

    Abstract Several antibacterial compounds have recently been discovered that potentially inhibit the activity of BamA, an essential subunit of a heterooligomer (the
    MeSH term(s) Escherichia coli/metabolism ; Escherichia coli Proteins/metabolism ; Bacterial Outer Membrane Proteins/metabolism ; Anti-Bacterial Agents/pharmacology ; Anti-Bacterial Agents/metabolism ; Protein Folding
    Chemical Substances Escherichia coli Proteins ; Bacterial Outer Membrane Proteins ; Anti-Bacterial Agents ; BamA protein, E coli
    Language English
    Publishing date 2022-09-27
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Intramural ; Research Support, N.I.H., Extramural
    ZDB-ID 2557172-2
    ISSN 2150-7511 ; 2161-2129
    ISSN (online) 2150-7511
    ISSN 2161-2129
    DOI 10.1128/mbio.02286-22
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: BamA forms a translocation channel for polypeptide export across the bacterial outer membrane.

    Doyle, Matthew Thomas / Bernstein, Harris David

    Molecular cell

    2021  Volume 81, Issue 9, Page(s) 2000–2012.e3

    Abstract: The β-barrel assembly machine (BAM) integrates β-barrel proteins into the outer membrane (OM) of Gram-negative bacteria. An essential BAM subunit (BamA) catalyzes integration by promoting the formation of a hybrid-barrel intermediate state between its ... ...

    Abstract The β-barrel assembly machine (BAM) integrates β-barrel proteins into the outer membrane (OM) of Gram-negative bacteria. An essential BAM subunit (BamA) catalyzes integration by promoting the formation of a hybrid-barrel intermediate state between its own β-barrel domain and that of its client proteins. Here we show that in addition to catalyzing the integration of β-barrel proteins, BamA functions as a polypeptide export channel. In vivo structural mapping via intermolecular disulfide crosslinking showed that the extracellular "passenger" domain of a member of the "autotransporter" superfamily of virulence factors traverses the OM through the BamA β-barrel lumen. Furthermore, we demonstrate that a highly conserved residue within autotransporter β-barrels is required to position the passenger inside BamA to initiate translocation and that during translocation, the passenger stabilizes the hybrid-barrel state. Our results not only establish a new function for BamA but also unify the divergent functions of BamA and other "Omp85" superfamily transporters.
    MeSH term(s) Bacterial Outer Membrane/metabolism ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Outer Membrane Proteins/metabolism ; Biological Transport ; Conserved Sequence ; Escherichia coli K12/genetics ; Escherichia coli K12/metabolism ; Escherichia coli Proteins/genetics ; Escherichia coli Proteins/metabolism ; Protein Conformation ; Protein Folding ; Structure-Activity Relationship ; Tryptophan
    Chemical Substances Bacterial Outer Membrane Proteins ; BamA protein, E coli ; Escherichia coli Proteins ; Tryptophan (8DUH1N11BX)
    Language English
    Publishing date 2021-03-10
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Intramural
    ZDB-ID 1415236-8
    ISSN 1097-4164 ; 1097-2765
    ISSN (online) 1097-4164
    ISSN 1097-2765
    DOI 10.1016/j.molcel.2021.02.023
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    Zs.A 5055: Show issues Location:
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  10. Article: Influence of ovarian torsion on reproductive outcomes and mode of delivery.

    Silberstein, Tali / Freud, Amir / Baumfeld, Yael / Sheiner, Eyal / Weintraub, Adi Yehuda / Mastrolia, Salvatore Andrea / Trojano, Giuseppe / Bernstein, Eli Harris / Schwarzman, Polina

    Frontiers in medicine

    2024  Volume 11, Page(s) 1370409

    Abstract: Purpose: To investigate differences in reproductive outcomes among patients before and following ovarian torsion.: Study design: In this retrospective cohort study, we investigated the reproductive outcomes of patients who underwent surgery for ... ...

    Abstract Purpose: To investigate differences in reproductive outcomes among patients before and following ovarian torsion.
    Study design: In this retrospective cohort study, we investigated the reproductive outcomes of patients who underwent surgery for ovarian torsion between 1988 and 2015 in a tertiary medical center. Data on deliveries before and after ovarian torsion were compared.
    Results: During the study period, 199 women underwent surgery due to ovarian torsion. The majority (91.4%;
    Conclusion: Surgically treated ovarian torsion does not appear to negatively influence fertility and live birth potential.
    Language English
    Publishing date 2024-03-27
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2775999-4
    ISSN 2296-858X
    ISSN 2296-858X
    DOI 10.3389/fmed.2024.1370409
    Database MEDical Literature Analysis and Retrieval System OnLINE

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