BoCool at 15:14, 28 October 2008

2008-10-28T15:14:36Z

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== Lsr (AI-2) cell signaling system ==

'''Responsible''': Kelly Davis, Xiao Zhu

'''Signal molecule''': AI-2 (furanosyl borate diester in V. harveyi, a variety of other molecules in other species), all are derived from DPD. [http://iai.asm.org/cgi/reprint/73/6/3197.pdf AI-2 is R-THMF in E. coli]

[http://www.biomedcentral.com/content/pdf/1471-2148-4-36.pdf]

'''Bacterial species''':

lsrA,B,C,D,F,G,R,K: Escherichia coli HS, SMS-3-5, str. K12 substr. MG1655, and substr. DH10B.

lsrE:Escherichia coli str. K12 substr. MG1655

LuxS:Escherichia coli HS, SMS-3-5, APEC O1, str. K12 substr. MG1655, substr. DH10B, and UTI89.

'''Receiver protein''': LsrR protein receives signal from sensor protein

'''Signal molecule synthase''': Pfs enzyme, then LuxS autoinducer synthase

'''Target genes''': lsr operon, including ABC transporter and LsrK kinase

'''Regulation''': LsrR represses the lsr operon, derepression by phospho-AI-2; catabolite repression influences AI-2 accumulation through the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex, which directly stimulates transcription of the lsr operon and indirectly represses luxS expression.cAMP-CRP is shown to bind to a cAMP receptor protein (CRP) binding site located in the upstream region of the lsr promoter and works with the LsrR repressor to regulate AI-2 uptake.

'''Note:''' AI-2 is synthesized and secreted during exponential growth and is imported in stationary phase when glucose becomes limiting. In the presence of glucose, AI-2 is not imported because the lsr operon is not transcribed due to camp-CAP mediated repression. Both glycerol and G3P(glycerol 3-phosphate) repress lsr transcription, while the majority repression comes from G3P. DHAP represses lsr transcription by a cAMP-CAP-independent mechanism involving LsrR.

'''Parts Needed:'''

LsrR pro/term

LsrK

LsrACDB (transport)

LsrFGE (catabolic)

LuxS

Pfs enzyme (?)

http://gcat.davidson.edu/GcatWiki/images/b/b8/N654260305_1291548_2335.jpg

'''Note:'''

lsrB encodes the periplasmic AI-2 binding protein

lsrC & lsrD encode the channel proteins

lsrA encodes the ATPase that provides energy for AI-2 transport

lsrF is similar to genes specifying aldolases

lsrG encodes a protein with an unknown function.

[http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=5591389&ordinalpos=26&itool=EntrezSystem2.PEntrez.Gene.Gene_ResultsPanel.Gene_RVDocSum tam: trans-aconitate 2-methyltransferase, also known as lsrE or yneD] [http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=6061192&ordinalpos=10&itool=EntrezSystem2.PEntrez.Gene.Gene_ResultsPanel.Gene_RVDocSum yneE:conserved inner membrane protein]

http://gcat.davidson.edu/GcatWiki/images/3/30/N654260305_1340817_550.jpg

[[Image:Har.JPG]]
[http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=55669965 R-THMF]
http://gcat.davidson.edu/GcatWiki/images/8/8c/S-DPD.gif
http://www.nature.com/nrmicro/journal/v3/n5/images/nrmicro1146-f2.gif

http://gcat.davidson.edu/GcatWiki/images/c/c9/Grl.jpg

DHAP: dihydroxyacetone phosphate.

http://gcat.davidson.edu/GcatWiki/images/9/9b/Grlw.jpg

'''References'''

[http://jb.asm.org/cgi/content/full/187/6/2066?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&titleabstract=lsrR&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT Cyclic AMP and cAMP Receptor Protein Influence both Synthesis and Uptake of Extracellular Autoinducer 2 in Escherichia coli]

[http://iai.asm.org/cgi/reprint/IAI.00550-07v1.pdf Global Effects of the Cell-to-Cell Signaling Molecules Autoinducer-2, Autoinducer-3, and Epinephrine in a luxS Mutant of Enterohemorrhagic Escherichia Coli]

[http://www.rsc.org/delivery/_ArticleLinking/DisplayHTMLArticleforfree.cfm?JournalCode=CC&Year=2005&ManuscriptID=b509396a&Iss=38 Shows how AI-2 is formed]

[http://www.jstor.org/sici?sici=0027-8424(20031125)100%3C14549%3ACCAB%3E2.0.CO%3B2-B&cookieSet=1 Signaling explained with graphics of AI-2 pathways]

[http://web.ebscohost.com/ehost/detail?vid=1&hid=116&sid=edfbf2f7-b0c8-40c3-8227-1cc94f134972%40sessionmgr108 Lsr-mediated transport and processing of AI-2 in Salmonella typhimurium]

[http://www.microbialcellfactories.com/content/pdf/1475-2859-1-5.pdf Review of AI-2 and other systems]

[http://jb.asm.org/cgi/content/full/189/16/6011?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&titleabstract=AI+2+LsrR&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT Quorum Sensing in Escherichia coli Is Signaled by AI-2/LsrR: Effects on Small RNA and Biofilm Architecture]

[http://jb.asm.org/cgi/content/full/187/1/238?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&titleabstract=quorum+sensing+AI-2&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT Regulation of Uptake and Processing of the Quorum-Sensing Autoinducer AI-2 in Escherichia coli]

'''Resources'''

[http://www.ommscientific.com/ AI-2/DPD]

[http://www.biomedcentral.com/content/pdf/1471-2180-8-98.pdf alternate AI-2 synthesis]

[http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=full_report&list_uids=5586283 lsrK gene in Entrez]

[http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=6062136&ordinalpos=9&itool=EntrezSystem2.PEntrez.Gene.Gene_ResultsPanel.Gene_RVDocSum#summary lsrR gene in Entrez]

[http://BioCyc.org/ECOLI/substring-search?type=NIL&object=lsr lsr nucleotide sequence in EcoCyc]

Transcription of LuxS (interaction with micA,gshA)

http://gcat.davidson.edu/GcatWiki/images/c/cb/N654260305_1347432_6212.jpg

Lsr - Revision history

BoCool at 15:14, 28 October 2008