LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 4 of total 4

Search options

  1. Article ; Online: Proximity biotinylation reveals novel secreted dense granule proteins of Toxoplasma gondii bradyzoites.

    Nadipuram, Santhosh Mukund / Thind, Amara Cervantes / Rayatpisheh, Shima / Wohlschlegel, James Akira / Bradley, Peter John

    PloS one

    2020  Volume 15, Issue 5, Page(s) e0232552

    Abstract: Toxoplasma gondii is an obligate intracellular parasite which is capable of establishing life-long chronic infection in any mammalian host. During the intracellular life cycle, the parasite secretes an array of proteins into the parasitophorous vacuole ( ... ...

    Abstract Toxoplasma gondii is an obligate intracellular parasite which is capable of establishing life-long chronic infection in any mammalian host. During the intracellular life cycle, the parasite secretes an array of proteins into the parasitophorous vacuole (PV) where it resides. Specialized organelles called the dense granules secrete GRA proteins that are known to participate in nutrient acquisition, immune evasion, and host cell-cycle manipulation. Although many GRAs have been discovered which are expressed during the acute infection mediated by tachyzoites, little is known about those that participate in the chronic infection mediated by the bradyzoite form of the parasite. In this study, we sought to uncover novel bradyzoite-upregulated GRA proteins using proximity biotinylation, which we previously used to examine the secreted proteome of the tachyzoites. Using a fusion of the bradyzoite upregulated protein MAG1 to BirA* as bait and a strain with improved switch efficiency, we identified a number of novel GRA proteins which are expressed in bradyzoites. After using the CRISPR/Cas9 system to characterize these proteins by gene knockout, we focused on one of these GRAs (GRA55) and found it was important for the establishment or maintenance of cysts in the mouse brain. These findings highlight new components of the GRA proteome of the tissue-cyst life stage of T. gondii and identify potential targets that are important for maintenance of parasite persistence in vivo.
    MeSH term(s) Animals ; Biotinylation ; Brain/metabolism ; Brain/parasitology ; CRISPR-Cas Systems ; Female ; Gene Knockout Techniques ; Genes, Protozoan ; Humans ; Life Cycle Stages ; Mice ; Mice, Inbred C57BL ; Proteome/metabolism ; Protozoan Proteins/genetics ; Protozoan Proteins/metabolism ; Toxoplasma/genetics ; Toxoplasma/growth & development ; Toxoplasma/physiology ; Toxoplasmosis, Animal/metabolism ; Toxoplasmosis, Animal/parasitology ; Toxoplasmosis, Cerebral/metabolism ; Toxoplasmosis, Cerebral/parasitology ; Vacuoles/metabolism ; Virulence
    Chemical Substances Proteome ; Protozoan Proteins
    Language English
    Publishing date 2020-05-06
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0232552
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: A photoactivatable crosslinking system reveals protein interactions in the Toxoplasma gondii inner membrane complex.

    Choi, Charles Paul / Moon, Andy Seong / Back, Peter Sungmin / Jami-Alahmadi, Yasaman / Vashisht, Ajay Amar / Wohlschlegel, James Akira / Bradley, Peter John

    PLoS biology

    2019  Volume 17, Issue 10, Page(s) e3000475

    Abstract: The Toxoplasma gondii inner membrane complex (IMC) is an important organelle involved in parasite motility and replication. The IMC resides beneath the parasite's plasma membrane and is composed of both membrane and cytoskeletal components. Although the ... ...

    Abstract The Toxoplasma gondii inner membrane complex (IMC) is an important organelle involved in parasite motility and replication. The IMC resides beneath the parasite's plasma membrane and is composed of both membrane and cytoskeletal components. Although the protein composition of the IMC is becoming better understood, the protein-protein associations that enable proper functioning of the organelle remain largely unknown. Determining protein interactions in the IMC cytoskeletal network is particularly challenging, as disrupting the cytoskeleton requires conditions that disrupt protein complexes. To circumvent this problem, we demonstrate the application of a photoreactive unnatural amino acid (UAA) crosslinking system to capture protein interactions in the native intracellular environment. In addition to identifying binding partners, the UAA approach maps the binding interface of the bait protein used for crosslinking, providing structural information of the interacting proteins. We apply this technology to the essential IMC protein ILP1 and demonstrate that distinct regions of its C-terminal coiled-coil domain crosslink to the alveolins IMC3 and IMC6, as well as IMC27. We also show that the IMC3 C-terminal domain and the IMC6 N-terminal domain are necessary for binding to ILP1, further mapping interactions between ILP1 and the cytoskeleton. Together, this study develops a new approach to study protein-protein interactions in Toxoplasma and provides the first insight into the architecture of the cytoskeletal network of the apicomplexan IMC.
    MeSH term(s) Azides/chemistry ; Cell Membrane/genetics ; Cell Membrane/metabolism ; Cell Membrane/ultrastructure ; Cross-Linking Reagents/chemistry ; Cytoskeletal Proteins/chemistry ; Cytoskeletal Proteins/genetics ; Cytoskeletal Proteins/metabolism ; Cytoskeleton/genetics ; Cytoskeleton/metabolism ; Cytoskeleton/ultrastructure ; Gene Expression ; Intracellular Membranes/metabolism ; Intracellular Membranes/ultrastructure ; Phenylalanine/analogs & derivatives ; Phenylalanine/chemistry ; Photochemical Processes ; Protein Binding ; Protein Interaction Domains and Motifs ; Protein Interaction Mapping/methods ; Protozoan Proteins/chemistry ; Protozoan Proteins/genetics ; Protozoan Proteins/metabolism ; Toxoplasma/genetics ; Toxoplasma/metabolism ; Toxoplasma/ultrastructure ; Ultraviolet Rays
    Chemical Substances Azides ; Cross-Linking Reagents ; Cytoskeletal Proteins ; Protozoan Proteins ; 4-azidophenylalanine (33173-53-4) ; Phenylalanine (47E5O17Y3R)
    Language English
    Publishing date 2019-10-04
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2126776-5
    ISSN 1545-7885 ; 1544-9173
    ISSN (online) 1545-7885
    ISSN 1544-9173
    DOI 10.1371/journal.pbio.3000475
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Fumarate Mediates a Chronic Proliferative Signal in Fumarate Hydratase-Inactivated Cancer Cells by Increasing Transcription and Translation of Ferritin Genes.

    Kerins, Michael John / Vashisht, Ajay Amar / Liang, Benjamin Xi-Tong / Duckworth, Spencer Jordan / Praslicka, Brandon John / Wohlschlegel, James Akira / Ooi, Aikseng

    Molecular and cellular biology

    2017  Volume 37, Issue 11

    Abstract: Germ line mutations of the gene encoding the tricarboxylic acid (TCA) cycle enzyme fumarate hydratase ( ...

    Abstract Germ line mutations of the gene encoding the tricarboxylic acid (TCA) cycle enzyme fumarate hydratase (
    MeSH term(s) Amino Acid Sequence ; Carcinoma, Renal Cell/enzymology ; Carcinoma, Renal Cell/genetics ; Carcinoma, Renal Cell/pathology ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Ferritins/genetics ; Forkhead Box Protein M1/metabolism ; Fumarate Hydratase/metabolism ; Fumarates/pharmacology ; Humans ; Intracellular Space/metabolism ; Iron Regulatory Protein 2/chemistry ; Iron Regulatory Protein 2/metabolism ; Kidney Neoplasms/enzymology ; Kidney Neoplasms/genetics ; Kidney Neoplasms/pathology ; Leiomyomatosis/enzymology ; Leiomyomatosis/genetics ; Leiomyomatosis/pathology ; Models, Biological ; NF-E2-Related Factor 2/metabolism ; Protein Biosynthesis/drug effects ; Signal Transduction/drug effects ; Succinic Acid/metabolism ; Transcription, Genetic/drug effects
    Chemical Substances FOXM1 protein, human ; Forkhead Box Protein M1 ; Fumarates ; NF-E2-Related Factor 2 ; NFE2L2 protein, human ; Ferritins (9007-73-2) ; Succinic Acid (AB6MNQ6J6L) ; Fumarate Hydratase (EC 4.2.1.2) ; IREB2 protein, human (EC 4.2.1.3) ; Iron Regulatory Protein 2 (EC 4.2.1.3)
    Language English
    Publishing date 2017-05-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00079-17
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Fumarate Mediates a Chronic Proliferative Signal in Fumarate Hydratase-Inactivated Cancer Cells by Increasing Transcription and Translation of Ferritin Genes

    Kerins, Michael John / Vashisht, Ajay Amar / Liang, Benjamin Xi-Tong / Duckworth, Spencer Jordan / Praslicka, Brandon John / Wohlschlegel, James Akira / Ooi, Aikseng

    Molecular and Cellular Biology. 2017 June 1, v. 37, no. 11 p.e00079-17-

    2017  

    Abstract: Germ line mutations of the gene encoding the tricarboxylic acid (TCA) cycle enzyme fumarate hydratase (FH) cause a hereditary cancer syndrome known as hereditary leiomyomatosis and renal cell cancer (HLRCC). HLRCC-associated tumors harbor biallelic FH ... ...

    Abstract Germ line mutations of the gene encoding the tricarboxylic acid (TCA) cycle enzyme fumarate hydratase (FH) cause a hereditary cancer syndrome known as hereditary leiomyomatosis and renal cell cancer (HLRCC). HLRCC-associated tumors harbor biallelic FH inactivation that results in the accumulation of the TCA cycle metabolite fumarate. Although it is known that fumarate accumulation can alter cellular signaling, if and how fumarate confers a growth advantage remain unclear. Here we show that fumarate accumulation confers a chronic proliferative signal by disrupting cellular iron signaling. Specifically, fumarate covalently modifies cysteine residues on iron regulatory protein 2 (IRP2), rendering it unable to repress ferritin mRNA translation. Simultaneously, fumarate increases ferritin gene transcription by activating the NRF2 (nuclear factor [erythroid-derived 2]-like 2) transcription factor. In turn, increased ferritin protein levels promote the expression of the promitotic transcription factor FOXM1 (Forkhead box protein M1). Consistently, clinical HLRCC tissues showed increased expression levels of both FOXM1 and its proliferation-associated target genes. This finding demonstrates how FH inactivation can endow cells with a growth advantage.
    Keywords chemical bonding ; cysteine ; ferritin ; fumarate hydratase ; fumarates ; genes ; germ cells ; metabolites ; regulatory proteins ; renal cell carcinoma ; transcription (genetics) ; transcription factors ; tricarboxylic acid cycle ; FH ; FOXM1 ; fumarate ; HLRCC ; NRF2
    Language English
    Dates of publication 2017-0601
    Publishing place Taylor & Francis
    Document type Article ; Online
    ZDB-ID 779397-2
    ISSN 1098-5549 ; 0270-7306
    ISSN (online) 1098-5549
    ISSN 0270-7306
    DOI 10.1128/MCB.00079-17
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

To top