Characterization of iron transport systems in Caulobacter crescentus

• Grant number: 17/02127-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2017
• End date: October 31, 2018
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Marilis Do Valle Marques
• Grantee: Naara Marcondes dos Santos
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 14/04046-8 - Regulatory networks of bacterial stress response, AP.TEM

Abstract

Caulobacter crescentus is an ±-proteobacteria that lives in aquatic environments and is a key organism for the study of the cell cycle in prokaryotes, due to its asymmetric cell cycle that results in two distinct daughter cells. As an oligotrophic organism, it is able to colonize environments with low nutrient concentration and organic matter availability, experiencing nutritional stress. Iron is available in the Earth's surface and it can be found in two oxidation states: the ferrous state (Fe²+) and the ferric state (Fe³+). Throughout evolution, microorganisms have developed new strategies for iron acquisition. In the case of gram-negative bacteria, the uptake occurs with the help of siderophores, which are small molecules that are able to bind to extracellular iron ions and are eventually internalized by transport systems that include outer membrane TonB-dependent receptors. This process requires energy of the proton motive force that is transmitted to the outer membrane receptors throughout the TonB-ExbB-ExbD system. This project proposes to study the TonB-dependent transporters and other iron transport systems in Caulobacter crescentus. For this, null strains will be constructed with the knockout of genes encoding possible iron transporters, e those encoding the two TonB proteins, and to analyze its siderophore utilization phenotype. Moreover, the heme transporter HutA will be characterized biochemically, in order to define its transport parameters and to identify the amino acid residues important for heme recognition. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LEADEN, LAURA; SILVA, LARISSA G.; RIBEIRO, RODOLFO A.; DOS SANTOS, NAARA M.; LORENZETTI, ALAN P. R.; ALEGRIA, THIAGO G. P.; SCHULZ, MARIANE L.; MEDEIROS, MARISA H. G.; KOIDE, TIE; MARQUES, V, MARILIS. Iron Deficiency Generates Oxidative Stress and Activation of the SOS Response in Caulobacter crescentus. FRONTIERS IN MICROBIOLOGY, v. 9, AUG 28 2018. (14/04046-8, 16/06378-3, 15/07386-7, 17/02127-9, 15/21038-1, 17/03052-2)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SANTOS, Naara Marcondes dos. Study of iron transport in Caulobacter crescentus.. 2019. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) São Paulo.