title: A proteomic approach to understand the role of the outer membrane porins in the organic solvent-tolerance of Pseudomonas aeruginosa PseA.
abstract: Solvent-tolerant microbes have the unique ability to thrive in presence of organic solvents. The present study describes the effect of increasing hydrophobicity (log Pow values) of organic solvents on the outer membrane proteome of the solvent-tolerant Pseudomonas aeruginosa PseA cells. The cells were grown in a medium containing 33% (v/v) alkanes of increasing log Pow values. The outer membrane proteins were extracted by alkaline extraction from the late log phase cells and changes in the protein expression were studied by 2-D gel electrophoresis. Seven protein spots showed significant differential expression in the solvent exposed cells. The tryptic digest of the differentially regulated proteins were identified by LC-ESI MS/MS. The identity of these proteins matched with porins OprD, OprE, OprF, OprH, Opr86, LPS assembly protein and A-type flagellin. The reported pI values of these proteins were in the range of 4.94-8.67 and the molecular weights were in the range of 19.5-104.5 kDa. The results suggest significant down-regulation of the A-type flagellin, OprF and OprD and up-regulation of OprE, OprH, Opr86 and LPS assembly protein in presence of organic solvents. OprF and OprD are implicated in antibiotic uptake and outer membrane stability, whereas A-type flagellin confers motility and chemotaxis. Up-regulated OprE is an anaerobically-induced porin while Opr86 is responsible for transport of small molecules and assembly of the outer membrane proteins. Differential regulation of the above porins clearly indicates their role in adaptation to solvent exposure.
authors.affiliation: Enzyme and Microbial Biochemistry Lab, Department of Chemistry, Indian Institute of Technology, Delhi, New Delhi, India.
authors.forename: R
authors.initials: R
authors.lastname: Hemamalini
authors.affiliation: Enzyme and Microbial Biochemistry Lab, Department of Chemistry, Indian Institute of Technology, Delhi, New Delhi, India.
authors.forename: Sunil
authors.initials: S
authors.lastname: Khare
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000473:Alkanes / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D018272:Porins / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012997:Solvents / Q000494:pharmacology*
chemical_list: D000473:Alkanes; D001425:Bacterial Outer Membrane Proteins; D018272:Porins; D020543:Proteome; D012997:Solvents
references.citation: J Bacteriol. 1989 Jun;171(6):3304-9
references.pmid: 2498289
references.citation: Int J Med Microbiol. 2012 Mar;302(2):63-8
references.pmid: 22226846
references.citation: Proc Natl Acad Sci U S A. 2011 Feb 8;108(6):2486-91
references.pmid: 21257904
references.citation: J Bacteriol. 2001 Jul;183(14):4127-33
references.pmid: 11418551
references.citation: Mol Biosyst. 2012 Nov;8(11):3017-27
references.pmid: 22956018
references.citation: J Mol Biol. 1982 May 5;157(1):105-32
references.pmid: 7108955
references.citation: Mol Microbiol. 1990 Jul;4(7):1069-75
references.pmid: 1700255
references.citation: Science. 2005 Jul 29;309(5735):774-7
references.pmid: 16051797
references.citation: Can J Microbiol. 2011 Apr;57(4):295-302
references.pmid: 21491981
references.citation: Lett Appl Microbiol. 2009 Sep;49(3):372-7
references.pmid: 19712193
references.citation: Curr Opin Biotechnol. 2012 Jun;23(3):415-21
references.pmid: 22155018
references.citation: BMC Genomics. 2012 May 31;13:215
references.pmid: 22651860
references.citation: Crit Rev Biotechnol. 2009;29(1):44-54
references.pmid: 19514902
references.citation: Mol Microbiol. 2000 Jul;37(2):239-53
references.pmid: 10931321
references.citation: J Biol Chem. 2006 Jun 16;281(24):16220-9
references.pmid: 16595653
references.citation: J Proteomics. 2010 Jun 16;73(8):1461-78
references.pmid: 20153847
references.citation: Annu Rev Microbiol. 2002;56:743-68
references.pmid: 12142492
references.citation: Infect Immun. 2011 Mar;79(3):1176-86
references.pmid: 21189321
references.citation: Microbiology (Reading). 2003 May;149(Pt 5):1265-1273
references.pmid: 12724388
references.citation: Anal Biochem. 1976 May 7;72:248-54
references.pmid: 942051
references.citation: J Bacteriol. 1998 Jul;180(14):3556-62
references.pmid: 9657997
references.citation: Biotechnol Prog. 2004 May-Jun;20(3):655-60
references.pmid: 15176865
references.citation: Biotechnol Bioeng. 1993 Sep 5;42(6):747-58
references.pmid: 18613108
references.citation: J Biosci Bioeng. 2005 Apr;99(4):378-82
references.pmid: 16233805
references.citation: Eur J Biochem. 2000 May;267(10):2871-81
references.pmid: 10806384
references.citation: J Biol Chem. 1990 Sep 15;265(26):15680-4
references.pmid: 2118530
references.citation: AMB Express. 2012 Nov 13;2(1):58
references.pmid: 23148659
references.citation: Microbiol Rev. 1995 Jun;59(2):201-22
references.pmid: 7603409
references.citation: Bioresour Technol. 2006 Oct;97(15):1788-93
references.pmid: 16242320
references.citation: Environ Sci Technol. 2009 Nov 1;43(21):8406-15
references.pmid: 19924977
references.citation: J Bacteriol. 2008 Jun;190(11):3969-78
references.pmid: 18390657
references.citation: FEBS Lett. 1996 Nov 4;396(2-3):213-7
references.pmid: 8914989