The importance of calcium (Ca2+) as a cell regulator is well established in eukaryotes. However, the role ofCa2+ in prokaryotes still remains elusive. Recent experimental work has suggested that Ca2+ ions may playa regulatory role in prokaryotic organisms. An essential step toward an increased understanding of the roleof Ca2+ is the identification and characterization of Ca2+ binding proteins (CaBPs). In eukaryotes, CaBPsare involved in the regulation of multiple cellular events including: cell differentiation, gene expression,transport mechanisms and others. Our preliminary data indicates that several CaBPs are present in bacteria(E. coli, B. subtilis and B. pertussis). These proteins share similar biochemical characteristics with eukaryoticCaBPs, including calmodulin (CaM). In an effort to isolate and sequence these proteins we analyzed crudecell lysates by 2D-electrophoresis followed by mass spectrometry. Most of the proteins found with CaBPcharacteristics are associated with stress responses. Based on these initial findings and other published datathe purpose of this application is: 1) to map changes in protein expression as a function of cytosolic Ca2+levels during both optimal growth conditions and during induced stress responses (heat/cold/pH shock). 2) tostudy the role of Ca2+ ions in transcription and establish the nature of the calcium regulon. The long-termgoal of this research is to illuminate the role of Ca2+ in bacteria. We hypothesize that CaBPs play animportant role in Ca2+ homeostasis and that Ca2+ ions are involved in the regulation of several intracellularprocesses in bacterial cells. In particular, we hypothesize that the intracellular concentration of Ca2+ ions areinvolved in the regulation of stress response proteins with associated changes in gene expression. Thefollowing specific aims were developed: 1) To characterize further the previously identified CaBPs and toidentify new CaBPs that are involved in the bacterial response to changes in calcium levels 2) To identifyand characterize the adaptive mechanisms utilized by cells to maintain calcium homeostasis 3) To determinethe role of calcium in stress-related proteomic changes 4) To investigate the specific genomic changes thatoccur in bacteria in response to changing calcium levels. This study will lead to better understanding of basiccell biology and physiology of both pathogenic and environmental microorganisms and may lead todevelopment of new therapeutics for the control of pathogenic bacteria.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Minority Biomedical Research Support - MBRS (S06)
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University of Texas El Paso
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Rocha-Gutiérrez, Beatriz A; Lee, Wen-Yee; Shane Walker, W (2016) Mass balance and mass loading of polybrominated diphenyl ethers (PBDEs) in a tertiary wastewater treatment plant using SBSE-TD-GC/MS. Water Sci Technol 73:302-8
Vargas-Medrano, Javier; Sierra-Fonseca, Jorge A; Plenge-Tellechea, Luis F (2016) 1,2-Dichlorobenzene affects the formation of the phosphoenzyme stage during the catalytic cycle of the Ca(2+)-ATPase from sarcoplasmic reticulum. BMC Biochem 17:5
Buhaya, Munir H; Galvan, Steven; Maldonado, Rosa A (2015) Incidence of Trypanosoma cruzi infection in triatomines collected at Indio Mountains Research Station. Acta Trop 150:97-9
Vasquez, Miguel A; Iniguez, Eva; Das, Umashankar et al. (2015) Evaluation of ?,?-unsaturated ketones as antileishmanial agents. Antimicrob Agents Chemother 59:3598-601
Dagda, Ruben K; Gasanov, Sardar E; Zhang, Boris et al. (2014) Molecular models of the Mojave rattlesnake (Crotalus scutulatus scutulatus) venom metalloproteinases reveal a structural basis for differences in hemorrhagic activities. J Biol Phys 40:193-216
Serna, Carylinda; Lara, Joshua A; Rodrigues, Silas P et al. (2014) A synthetic peptide from Trypanosoma cruzi mucin-like associated surface protein as candidate for a vaccine against Chagas disease. Vaccine 32:3525-32
Rodrigues, Marcio L; Nakayasu, Ernesto S; Almeida, Igor C et al. (2014) The impact of proteomics on the understanding of functions and biogenesis of fungal extracellular vesicles. J Proteomics 97:177-86
Rico-Martínez, Roberto; Walsh, Elizabeth J (2013) Sexual Reproductive Biology of a Colonial Rotifer Sinantherina socialis (Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species? Mar Freshw Behav Physiol 46:419-430
Jin, Seoweon; Staniswalis, Joan G; Mallawaarachchi, Indika (2013) Principal Differential Analysis with a Continuous Covariate: Low Dimensional Approximations for Functional Data. J Stat Comput Simul 83:
Dagda, Ruben K; Gasanov, Sardar; De La Oiii, Ysidro et al. (2013) Genetic Basis for Variation of Metalloproteinase-Associated Biochemical Activity in Venom of the Mojave Rattlesnake (Crotalus scutulatus scutulatus). Biochem Res Int 2013:251474

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