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Antioxidant systems in seeds: Functions of 1-Cys Peroxiredoxin and Ascorbate during embryogenesis and germination.

Posted by: University of Sao Paulo

Posted date: May-24-2019

Location: Sao Paulo, SP

<p class="MsoNormal"><span class="tlid-translation"><span style="font-size:
14.0pt;line-height:115%;mso-ansi-language:EN" lang="EN">PD Fellowship in Redox Processes and Seed Biology</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><span style="mso-ansi-language:
EN" lang="EN"> </span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Title</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: Antioxidant systems in seeds: Functions of 1-Cys Peroxiredoxin and Ascorbate during embryogenesis and germination.</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Number of positions</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: 1</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Principal investigator</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: Luis E. S. Netto</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Unit/Instituition</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: </span></span><span style="mso-ansi-language:EN" lang="EN">Instituto de Biociências -USP</span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Deadline for submissions</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: 06-13-2019</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Publishing date</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: </span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:EN" lang="EN">Address</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:EN" lang="EN">: Rua do Matão, 277</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><span style="mso-ansi-language:
EN" lang="EN"><span style="mso-tab-count:1">                </span></span></span><span class="tlid-translation"><span style="mso-ansi-language:PT-BR">Departamento de Genética e Biologia</span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><span style="mso-ansi-language:
PT-BR"> </span></span></p>
<p class="MsoNormal"><span class="tlid-translation"><b style="mso-bidi-font-weight:
normal"><span style="mso-ansi-language:PT-BR">E-mail for proposal submission</span></b></span><span class="tlid-translation"><span style="mso-ansi-language:PT-BR">: </span></span><span style="mso-ansi-language:PT-BR">nettoles(at)ib.usp.br</span></p>
<p style="margin:0cm;margin-bottom:.0001pt;line-height:150%"><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:PT-BR">ABSTRACT OF THE PROPOSAL </span></b></p>
<p style="margin:0cm;margin-bottom:.0001pt;line-height:150%"><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:PT-BR"> </span></b></p>
<p style="margin:0cm;margin-bottom:.0001pt;text-align:justify;text-indent:1.0cm;
line-height:150%"><span lang="EN-US">Our research group investigates the mechanisms related to Cys-based peroxidases, such as peroxiredoxin (Prx) enzymes. We have shown that sulfenic acids (R-Cys-SOH) in enzymes of the 1-Cys Prx class can be reduced by ascorbate (vitamin C) (Monteiro et al., 2007 <i style="mso-bidi-font-style:normal">Proc. Natl. Acad. Sci USA</i>), challenging the paradigm that 1-Cys Prx are specifically reduced by thiols (RSH). Thus sulfenic acid / ascorbate represents a new redox pair, whose biological relevance still needs to be assessed.</span></p>
<p style="margin:0cm;margin-bottom:.0001pt;text-align:justify;text-indent:1.0cm;
line-height:150%"><span lang="EN-US">Our current challenge is to demonstrate that ascorbate can compete with other cellular reducing systems (i.e. Trx or Grx / GSH) for sulfenic acid reduction. The concentrations of these reductants in the different cellular compartments is one of the factors that can determine which system will prevail.</span></p>
<p style="margin:0cm;margin-bottom:.0001pt;text-align:justify;text-indent:1.0cm;
line-height:150%"><span lang="EN-US">Plants present very high concentrations of ascorbate (3-30 mM) in several cell compartments (Zechmann et al., 2011, Zechmann 2014). On the other hand, 1-Cys Prx of plants is preferentially expressed in embryonic tissues, mainly in nuclei of seed cells and in some cases diffused in the cytoplasm (Stacy et al., 1996, 1999). Other reductive systems in addition to ascorbate, such as Thioredoxin (Trx) and Trx Reductase (TrxR) are co-localized with PER1 during seed development, including in nuclei of germinating seeds under stress (Pulido et al., 2009).</span></p>
<p style="margin:0cm;margin-bottom:.0001pt;text-align:justify;text-indent:1.0cm;
line-height:150%"><span lang="EN-US">Therefore, understanding the biological significance of 1-Cys Prx reductants requires an integrated analysis, involving determination of kinetic parameters (such as <i style="mso-bidi-font-style:
normal">kcat</i> and Km); the distribution of the possible reductants during the life cycle of the seeds; in addition to phenotypes associated with genetic mutants. The antioxidant systems of seeds of two plants: <i style="mso-bidi-font-style:normal">Arabidopsis thaliana</i> (a model organism) and <i style="mso-bidi-font-style:normal">Araucaria angustifolia</i> (Brazilian pine) will be analyzed, with the collaboration of research groups led by Dr. Marie-Anne Van Sluys and Eny I.S. Floh from Department of Botany - Institute of Biosciences - USP.</span></p>
<p style="margin:0cm;margin-bottom:.0001pt;text-align:justify;text-indent:1.0cm;
line-height:150%"><b style="mso-bidi-font-weight:normal"><span lang="EN-US">CANDIDATE PROFILE</span></b></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">The position is opened to a young scientist with a doctorate in Biochemistry, Chemistry, Biology or related areas, with experience in molecular biology techniques, including expression and purification of proteins. Previous experience in techniques related to genetic manipulations of plants, embryogenesis and seed development is desirable, but not required.</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">The candidate must have obtained a PhD degree for a maximum of seven years and have a proven record of published papers, demonstrating capacity to act in the development of the project. Candidates must have fluency in English and dedicate themselves fully and exclusively to the project activities.</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">The position is open to Brazilians and foreigners. The selected candidate will receive FAPESP Post-Doctoral Fellowship in the amount of R$ 7,373.10 per month and Technical Reserve equivalent to 15% of the annual value of the scholarship to meet unforeseen expenses directly related to the research activity.</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:14.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">REGISTRATION</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">Candidates should send the following documents to nettoles(at)ib.usp.br until 06/13/2019:</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">a) A letter of interest;</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">b) Curriculum vitae including a list of publications;</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">c) Contact information (e-mail, telephone) of two professionals who can provide letters of recommendation.</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US"> </span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span style="font-size:12.0pt;line-height:150%;font-family:
"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"" lang="EN-US">More information on the rules of FAPESP governing the operation of postdoctoral fellowships is available at www.fapesp.br/bolsas/pd.</span></p>
<p class="MsoNormal" style="text-align:justify;text-indent:1.0cm;line-height:
150%"><span lang="EN-US"> </span></p>
Job Title Antioxidant systems in seeds: Functions of 1-Cys Peroxiredoxin and Ascorbate during embryogenesis and germination.
Post Details
Email nettoles(at)ib.usp.br
Employer's Website http
Category
Job Discipline Job Discipline -> Molecular Biology
Job Classification Job Classification -> Postdoctoral Researcher
Job Type Job Type -> Full-time
Location Sao Paulo, SP
Key Words postdoc, ascorbate, seed, thiol, peroxide
Start Date 06-20-2019
Deadline Jun-13-2019