1
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Luo Y, Barrios-Rodiles M, Gupta GD, Zhang YY, Ogunjimi AA, Bashkurov M, Tkach JM, Underhill AQ, Zhang L, Bourmoum M, Wrana JL, Pelletier L. Atypical function of a centrosomal module in WNT signalling drives contextual cancer cell motility. Nat Commun 2019; 10:2356. [PMID: 31142743 PMCID: PMC6541620 DOI: 10.1038/s41467-019-10241-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 04/29/2019] [Indexed: 02/06/2023] Open
Abstract
Centrosomes control cell motility, polarity and migration that is thought to be mediated by their microtubule-organizing capacity. Here we demonstrate that WNT signalling drives a distinct form of non-directional cell motility that requires a key centrosome module, but not microtubules or centrosomes. Upon exosome mobilization of PCP-proteins, we show that DVL2 orchestrates recruitment of a CEP192-PLK4/AURKB complex to the cell cortex where PLK4/AURKB act redundantly to drive protrusive activity and cell motility. This is mediated by coordination of formin-dependent actin remodelling through displacement of cortically localized DAAM1 for DAAM2. Furthermore, abnormal expression of PLK4, AURKB and DAAM1 is associated with poor outcomes in breast and bladder cancers. Thus, a centrosomal module plays an atypical function in WNT signalling and actin nucleation that is critical for cancer cell motility and is associated with more aggressive cancers. These studies have broad implications in how contextual signalling controls distinct modes of cell migration. Centrosomes function in cell migration by organizing microtubules. Here, Luo et al. surprisingly show that centrosome proteins also control migration after recruitment by Wnt-PCP proteins to the cell cortex, leading to actin remodelling and protrusive activity relevant to aggressive cancer motility.
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Affiliation(s)
- Yi Luo
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Miriam Barrios-Rodiles
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Gagan D Gupta
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, ON, M5B 2K3, Canada
| | - Ying Y Zhang
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Abiodun A Ogunjimi
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Mikhail Bashkurov
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Johnny M Tkach
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Ainsley Q Underhill
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Liang Zhang
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Mohamed Bourmoum
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Jeffrey L Wrana
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Laurence Pelletier
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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2
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Shnitsar I, Bashkurov M, Masson GR, Ogunjimi AA, Mosessian S, Cabeza EA, Hirsch CL, Trcka D, Gish G, Jiao J, Wu H, Winklbauer R, Williams RL, Pelletier L, Wrana JL, Barrios-Rodiles M. PTEN regulates cilia through Dishevelled. Nat Commun 2015; 6:8388. [PMID: 26399523 PMCID: PMC4598566 DOI: 10.1038/ncomms9388] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/17/2015] [Indexed: 01/26/2023] Open
Abstract
Cilia are hair-like cellular protrusions important in many aspects of eukaryotic biology. For instance, motile cilia enable fluid movement over epithelial surfaces, while primary (sensory) cilia play roles in cellular signalling. The molecular events underlying cilia dynamics, and particularly their disassembly, are not well understood. Phosphatase and tensin homologue (PTEN) is an extensively studied tumour suppressor, thought to primarily act by antagonizing PI3-kinase signalling. Here we demonstrate that PTEN plays an important role in multicilia formation and cilia disassembly by controlling the phosphorylation of Dishevelled (DVL), another ciliogenesis regulator. DVL is a central component of WNT signalling that plays a role during convergent extension movements, which we show here are also regulated by PTEN. Our studies identify a novel protein substrate for PTEN that couples PTEN to regulation of cilia dynamics and WNT signalling, thus advancing our understanding of potential underlying molecular etiologies of PTEN-related pathologies.
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Affiliation(s)
- Iryna Shnitsar
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Mikhail Bashkurov
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Glenn R Masson
- Protein and Nucleic Acid Chemistry Division, Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Abiodun A Ogunjimi
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Sherly Mosessian
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California 90095, USA
| | - Eduardo Aguiar Cabeza
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Calley L Hirsch
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Daniel Trcka
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Gerald Gish
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
| | - Jing Jiao
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California 90095, USA
| | - Hong Wu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, California 90095, USA
| | - Rudolf Winklbauer
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5
| | - Roger L Williams
- Protein and Nucleic Acid Chemistry Division, Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Laurence Pelletier
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Jeffrey L Wrana
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Miriam Barrios-Rodiles
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
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3
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Beyer TA, Weiss A, Khomchuk Y, Huang K, Ogunjimi AA, Varelas X, Wrana JL. Switch enhancers interpret TGF-β and Hippo signaling to control cell fate in human embryonic stem cells. Cell Rep 2013; 5:1611-24. [PMID: 24332857 DOI: 10.1016/j.celrep.2013.11.021] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 10/03/2013] [Accepted: 11/11/2013] [Indexed: 01/25/2023] Open
Abstract
A small toolkit of morphogens is used repeatedly to direct development, raising the question of how context dictates interpretation of the same cue. One example is the transforming growth factor β (TGF-β) pathway that in human embryonic stem cells fulfills two opposite functions: pluripotency maintenance and mesendoderm (ME) specification. Using proteomics coupled to analysis of genome occupancy, we uncover a regulatory complex composed of transcriptional effectors of the Hippo pathway (TAZ/YAP/TEAD), the TGF-β pathway (SMAD2/3), and the pluripotency regulator OCT4 (TSO). TSO collaborates with NuRD repressor complexes to buffer pluripotency gene expression while suppressing ME genes. Importantly, the SMAD DNA binding partner FOXH1, a major specifier of ME, is found near TSO elements, and upon fate specification we show that TSO is disrupted with subsequent SMAD-FOXH1 induction of ME. These studies define switch-enhancer elements and provide a framework to understand how cellular context dictates interpretation of the same morphogen signal in development.
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Affiliation(s)
- Tobias A Beyer
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Alexander Weiss
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Yuliya Khomchuk
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Kui Huang
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Abiodun A Ogunjimi
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Xaralabos Varelas
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Jeffrey L Wrana
- Center for Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada.
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Luga V, Zhang L, Viloria-Petit AM, Ogunjimi AA, Inanlou MR, Chiu E, Buchanan M, Hosein AN, Basik M, Wrana JL. Exosomes mediate stromal mobilization of autocrine Wnt-PCP signaling in breast cancer cell migration. Cell 2013; 151:1542-56. [PMID: 23260141 DOI: 10.1016/j.cell.2012.11.024] [Citation(s) in RCA: 985] [Impact Index Per Article: 89.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 09/06/2012] [Accepted: 11/09/2012] [Indexed: 12/19/2022]
Abstract
Stroma in the tumor microenvironment plays a critical role in cancer progression, but how it promotes metastasis is poorly understood. Exosomes are small vesicles secreted by many cell types and enable a potent mode of intercellular communication. Here, we report that fibroblast-secreted exosomes promote breast cancer cell (BCC) protrusive activity and motility via Wnt-planar cell polarity (PCP) signaling. We show that exosome-stimulated BCC protrusions display mutually exclusive localization of the core PCP complexes, Fzd-Dvl and Vangl-Pk. In orthotopic mouse models of breast cancer, coinjection of BCCs with fibroblasts dramatically enhances metastasis that is dependent on PCP signaling in BCCs and the exosome component, Cd81 in fibroblasts. Moreover, we demonstrate that trafficking in BCCs promotes tethering of autocrine Wnt11 to fibroblast-derived exosomes. This work reveals an intercellular communication pathway whereby fibroblast exosomes mobilize autocrine Wnt-PCP signaling to drive BCC invasive behavior.
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Affiliation(s)
- Valbona Luga
- Center for Systems Biology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
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5
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Ogunjimi AA, Wiesner S, Briant DJ, Varelas X, Sicheri F, Forman-Kay J, Wrana JL. The ubiquitin binding region of the Smurf HECT domain facilitates polyubiquitylation and binding of ubiquitylated substrates. J Biol Chem 2009; 285:6308-15. [PMID: 20026602 DOI: 10.1074/jbc.m109.044537] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Mono- and polyubiquitylation of proteins are key steps in a wide range of biological processes. However, the molecular mechanisms that mediate these different events are poorly understood. Here, we employed NMR spectroscopy to map a non-covalent ubiquitin binding surface (UBS) on the Smurf ubiquitin ligase HECT domain. Analysis of mutants of the HECT UBS reveal that interfering with the UBS surface blocked Smurf-dependent degradation of its substrate RhoA in cells. In vitro analysis revealed that the UBS was not required for UbcH7-dependent charging of the HECT catalytic cysteine. Surprisingly, although the UBS was required for polyubiquitylation of both Smurf itself and the Smurf substrate RhoA, it was not required for monoubiquitylation. Furthermore, we show that mutating the UBS interfered with efficient binding of a monoubiquitylated form of RhoA to the Smurf HECT domain. Our findings suggest the UBS promotes polyubiquitylation by stabilizing ubiquitylated substrate binding to the HECT domain.
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Affiliation(s)
- Abiodun A Ogunjimi
- Center for Systems Biology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
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6
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Wiesner S, Ogunjimi AA, Wang HR, Rotin D, Sicheri F, Wrana JL, Forman-Kay JD. Autoinhibition of the HECT-type ubiquitin ligase Smurf2 through its C2 domain. Cell 2007; 130:651-62. [PMID: 17719543 DOI: 10.1016/j.cell.2007.06.050] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 05/29/2007] [Accepted: 06/28/2007] [Indexed: 11/19/2022]
Abstract
Ubiquitination of proteins is an abundant modification that controls numerous cellular processes. Many Ubiquitin (Ub) protein ligases (E3s) target both their substrates and themselves for degradation. However, the mechanisms regulating their catalytic activity are largely unknown. The C2-WW-HECT-domain E3 Smurf2 downregulates transforming growth factor-beta (TGF-beta) signaling by targeting itself, the adaptor protein Smad7, and TGF-beta receptor kinases for degradation. Here, we demonstrate that an intramolecular interaction between the C2 and HECT domains inhibits Smurf2 activity, stabilizes Smurf2 levels in cells, and similarly inhibits certain other C2-WW-HECT-domain E3s. Using NMR analysis the C2 domain was shown to bind in the vicinity of the catalytic cysteine, where it interferes with Ub thioester formation. The HECT-binding domain of Smad7, which activates Smurf2, antagonizes this inhibitory interaction. Thus, interactions between C2 and HECT domains autoinhibit a subset of HECT-type E3s to protect them and their substrates from futile degradation in cells.
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Affiliation(s)
- Silke Wiesner
- Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
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7
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Abstract
The Rho family of small GTPases plays a key role in the dynamic regulation of the actin cytoskeleton that underlies various important cellular functions such as shape changes, migration, and polarity. We found that Smurf1, a HECT domain E3 ubiquitin ligase, could specifically target RhoA but not Cdc42 or Rac1 for degradation. Smurf1 interacts with the dominant inactive form of RhoA, RhoA N19, which binds constitutively to guanine nucleotide exchange factors (GEFs) in vivo. Smurf1 also interacts directly with either nucleotide-free or GDP-bound RhoA in vitro; however, loading with GTPgammaS inhibits the interaction. RhoA is ubiquitinated by wild-type Smurf1 but not the catalytic mutant of Smurf1 (C699A) in vivo and in vitro, indicating that RhoA is a direct substrate of Smurf1. In this chapter, we summarize the systems and methods used in the analyses of Smurf1-regulated RhoA ubiquitination and degradation.
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Affiliation(s)
- Hong-Rui Wang
- Mount Sinai Hospital, University of Toronto, Ontario, Canada
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8
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Ogunjimi AA, Briant DJ, Pece-Barbara N, Le Roy C, Di Guglielmo GM, Kavsak P, Rasmussen RK, Seet BT, Sicheri F, Wrana JL. Regulation of Smurf2 ubiquitin ligase activity by anchoring the E2 to the HECT domain. Mol Cell 2005; 19:297-308. [PMID: 16061177 DOI: 10.1016/j.molcel.2005.06.028] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 05/03/2005] [Accepted: 06/24/2005] [Indexed: 11/24/2022]
Abstract
The conjugation of ubiquitin to proteins involves a cascade of activating (E1), conjugating (E2), and ubiquitin-ligating (E3) type enzymes that commonly signal protein destruction. In TGFbeta signaling the inhibitory protein Smad7 recruits Smurf2, an E3 of the C2-WW-HECT domain class, to the TGFbeta receptor complex to facilitate receptor degradation. Here, we demonstrate that the amino-terminal domain (NTD) of Smad7 stimulates Smurf activity by recruiting the E2, UbcH7, to the HECT domain. A 2.1 A resolution X-ray crystal structure of the Smurf2 HECT domain reveals that it has a suboptimal E2 binding pocket that could be optimized by mutagenesis to generate a HECT domain that functions independently of Smad7 and potently inhibits TGFbeta signaling. Thus, E2 enzyme recognition by an E3 HECT enzyme is not constitutively competent and provides a point of control for regulating the ubiquitin ligase activity through the action of auxiliary proteins.
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Affiliation(s)
- Abiodun A Ogunjimi
- Programme in Molecular Biology and Cancer, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
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9
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Wang HR, Zhang Y, Ozdamar B, Ogunjimi AA, Alexandrova E, Thomsen GH, Wrana JL. Regulation of cell polarity and protrusion formation by targeting RhoA for degradation. Science 2003; 302:1775-9. [PMID: 14657501 DOI: 10.1126/science.1090772] [Citation(s) in RCA: 432] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The Rho family of small guanosine triphosphatases regulates actin cytoskeleton dynamics that underlie cellular functions such as cell shape changes, migration, and polarity. We found that Smurf1, a HECT domain E3 ubiquitin ligase, regulated cell polarity and protrusive activity and was required to maintain the transformed morphology and motility of a tumor cell. Atypical protein kinase C zeta (PKCzeta), an effector of the Cdc42/Rac1-PAR6 polarity complex, recruited Smurf1 to cellular protrusions, where it controlled the local level of RhoA. Smurf1 thus links the polarity complex to degradation of RhoA in lamellipodia and filopodia to prevent RhoA signaling during dynamic membrane movements.
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Affiliation(s)
- Hong-Rui Wang
- Program in Molecular Biology and Cancer, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto M56 1x5, Canada
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10
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Ogunjimi AA, Chandler JM, Gbenle GO, Olukoya DK, Akinrimisi EO. Heterologous expression of cry2 gene from a local strain of Bacillus thuringiensis isolated in Nigeria. Biotechnol Appl Biochem 2002; 36:241-6. [PMID: 12452809 DOI: 10.1042/ba20020053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A cry2 gene encoding a larvicidal crystal protein was isolated from a strain of Bacillus thuringiensis found in soil samples in Nigeria. This gene was cloned into plasmid pUC19 and subcloned into both pBluescript (sk(+/-)) and pPICZ alpha B placed under a T7/AOXI (alcohol oxidase I) promoter respectively and transformed into Escherichia coli and Pichia pastoris. Clones were induced for expression, and the cellular proteins extracted and analysed by SDS/PAGE. Integration of an insert into the yeast chromosome was confirmed by PCR amplification using AOXI primers designed to monitor the intactness of the insertion into the chromosome. The expression cassettes constructed were both expressed in E. coli strain (XL1-blue) and P. pastoris (SMD1168) respectively. An approximately 70 kDa recombinant toxin was obtained both in P. pastoris and E. coli in different quantities. Expression was confirmed by Northern-blot analysis of 2.0 kb transcripts, obtained from clones induced for RNA transcripts, which hybridized with a [(32)P]dCTP-labelled probe prepared from a 641 bp fragment of restriction-endonuclease- Hae II-digested PCR product of the cry2 gene.
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Affiliation(s)
- Abiodun A Ogunjimi
- Department of Biochemistry, College of Medicine, University of Lagos, P.M.B. 12003, Lagos, Nigeria.
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11
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Abstract
Six isolates of Bacillus thuringiensis isolated from soil samples confirmed to be toxic to mosquito larvae were differentiated using a PCR-Based technique. Three of these isolates initially identified using a serological technique were further differentiated with the PCR amplification of the delta-endotoxin target sequences. Using the total DNA of isolates as template, at least four isolates yielded amplicons one or all the crystal protein genes, cryI a, b, c, or II with sizes ranging from 238-1070 bp. None of these isolates yielded an amplicon for any of Cry IV A, B and D tested. Of the four isolates identified by PCR technique one isolate remained unidentified by serology.
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Affiliation(s)
- A A Ogunjimi
- Department of Biochemistry, College of Medicine of the University of Lagos, Nigeria
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Ogunjimi AA, Choudary PV. Adsorption of endogenous polyphenols relieves the inhibition by fruit juices and fresh produce of immuno-PCR detection of Escherichia coli O157:H7. FEMS Immunol Med Microbiol 1999; 23:213-20. [PMID: 10219593 DOI: 10.1111/j.1574-695x.1999.tb01241.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The immuno-polymerase chain reaction (PCR) approaches facilitate rapid (8 h) detection of Escherichia coli O157:H7 in contaminated dairy products and ground beef samples with detection sensitivities approaching 1 colony forming unit (cfu) g-1 ml-1. However, no PCR products were obtained when the method was applied to identify E. coli O157:H7 in tainted apple juice. Enzyme-linked immuno-assay (ELISA) results suggested non-specific binding of endogenous polyphenols (ubiquitous in plant products) to antibodies present on the surface of the immunobeads, making the latter unavailable for capturing the target bacteria Treatment of the test sample, prior to IMS, with a synthetic fining agent, polyvinylpyrrolidone, restored the full function and sensitivity of the immuno-PCR. The study demonstrates the suitability of the improved method as a generic strategy for rapid screening of fruit juices and plant produce for E. coli O157:H7.
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Affiliation(s)
- A A Ogunjimi
- Antibody Engineering Laboratory, University of California, Davis 95616-8584, USA
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14
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Olukoya DK, Ogunjimi AA, Abaelu AM. Plasmid profiles and antimicrobial susceptibility patterns of Vibrio cholerae O1 strain isolated during a recent outbreak in Nigeria. J Diarrhoeal Dis Res 1995; 13:118-21. [PMID: 7594312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In a study on the outbreak of cholera in Nigeria in 1992, 86 strains of Vibrio cholerae O1 (79 Ogawa serotype and 7 Inaba serotype) were isolated. Antimicrobial susceptibility testing and plasmid profile analysis of the strains were done. Most isolates were highly sensitive to ciprofloxacin, cefotaxime, chloramphenicol, gentamicin, erythromycin, nalidixic acid, and nitrofurantoin, and less sensitive to ampicillin, penicillin, cloxacillin, cotrimoxazole, streptomycin, and tetracycline. The strains showed 13 resistant patterns; the commonest resistant patterns were Apr, Smr, and ApTcr. A total of 41 (47.6%) strains contained one or more plasmid(s) with sizes ranging from 4.5 kilobase to 150 kilobase. Ten isolates were able to transfer resistant plasmids to Escherichia coli K-12 by conjugation. Antibiogram patterns distinguished more isolates than in plasmid profile analysis. Plasmids specifying resistance to ampicillin, tetracycline, and trimethoprim were found. The differing patterns of antibiogram and plasmid profiles indicated that many circulating strains were responsible for the last outbreak in the country.
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Affiliation(s)
- D K Olukoya
- Genetics Division, Nigerian Institute of Medical Research, Lagos, Nigeria
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15
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Daini OA, Olukoya DK, Ogunjimi AA. Genetic analysis of tetracycline-resistant plasmids in enteropathogenic Escherichia coli isolated from patients in Nigeria. J Diarrhoeal Dis Res 1995; 13:39-43. [PMID: 7657964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Genetic analysis of antibiotic-resistant plasmids from 102 serologically defined strains of enteropathogenic Escherichia coli from Nigeria was carried out. All the isolates were screened for susceptibility to antibiotics, and 47 were found resistant to tetracycline. A total of 138 plasmids was isolated by agarose gel electrophoresis. Transformation and conjugation experiments showed that 57.4% of the resistant strains carried R-plasmids ranging in sizes from 2 to 46 x 10(6) daltons. Plasmid-determined resistance to tetracycline, ampicillin and streptomycin was found. Restriction endonuclease analysis of three of the commonest plasmids: p1679, p529 and p1479 revealed relatedness with respect to function and structure. The DNA segment on which TcR gene is located on each of them was identified by cloning into the vector plasmid pGL101. The recombinant plasmids pOADI and pOAD2 gave full expression of TcR gene when transformed into E. coli DHI. Furthermore, the tetracycline-resistant strains were examined for their phenotypic behaviour with respect to tetracycline and its lipophilic analogs.
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Affiliation(s)
- O A Daini
- Department of Biochemistry, Obafemi Awolowo College of Health Sciences, Ogun State University, Ago-Iwoye, Nigeria
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16
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Olukoya DK, Ebigwei SI, Olasupo NA, Ogunjimi AA. Production of DogiK: an improved Ogi (Nigerian fermented weaning food) with potentials for use in diarrhoea control. J Trop Pediatr 1994; 40:108-13. [PMID: 8015024 DOI: 10.1093/tropej/40.2.108] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
As part of a programme to formulate foods to aid the control of diarrhoeal diseases, an improved ogi (the commonest weaning food in Nigeria) named DogiK has been developed. DogiK was produced by using Lactobacillus starter cultures with antimicrobial activity against diarrhoeagenic bacteria and also possessing amylolytic activity. The survival of diarrhoeagenic bacteria was investigated in locally-fermented ogi and in DogiK. The foods were inoculated with cell suspensions of Salmonella, Shigella, Campylobacter, Aeromonas, Pleisiomonas, Enteropathogenic and Enterotoxigenic Escherichia coli, Yersinia enterocolitica, and Vibrio cholerae. None of the diarrhoeagenic bacteria were detected in DogiK after 6 h whereas in the local ogi Salmonella, E. coli, and Shigella survived for 24 h or more, but showed a sharp decrease in numbers, while V. cholerae survived for 12 h. DogiK is active whether cooked or uncooked and exhibited inhibition of pathogens at neutral pH. It gives consistent quality. Preliminary investigation indicates possession of a better shelf life. Thus, DogiK may have a potential use in the prevention and treatment of diarrhoea.
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Affiliation(s)
- D K Olukoya
- Molecular Genetics & Biotechnology Unit, National Institute for Medical Research, Yaba, Lagos, Nigeria
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