Download Do cyanobacteria communicate with each other?

Do Cyanobacteria Communicate
With Each Other?
Bacterial Communication
Quorum Sensing
• Important to perform group functions
• Secretion of toxins to kill competitors,
production of luminescent compounds,
etc.
• Small numbers of bacteria don’t activate
their Quorum Sensing genes
Bacterial Communication
Quorum Sensing
• Gram negative bacteria secrete acylhomoserine
lactone (AHL) quorum sensing signals also
called Autoinducers (AI’s)
• These molecules can easily diffuse through the
membrane and are detected by proteins in the
cytoplasm
• In this way the gram negative bacteria can
communicate with each other
• When concentration of AI’s is high enough
(numbers of bacteria are high enough) it can
trigger genes to become expressed
Bacterial Communication
Hawaiian Bobtailed Squid
Euprymna scolopes
Vibrio fischeri
Light Organ
Containing Vibrio fischeri
http://www.genomenewsnetwork.org/articles/2004/01/09/squid.php
http://www.biologie.uni-hamburg.de/lehre/mikro/allgmi00/alg07f13.jpg
Induction of Bioluminescence
in Vibrio Fischeri
(Auto-induction)
growth
Cell
Density
bioluminescence
Time
Auto-induction in Vibrio Fischeri
AHL’s
LuxI
luxC
LuxR
luxD
luxA
luxB
luxE
Auto-induction in Vibrio Fischeri
AHL’s
Autoinducer
LuxR activated
binds
Moves to promoter
of luciferase
genes
LuxR
luxC
luxD
LuxI
luciferase
luxA
luxB
luxE
Gram Positive Communication
• Gram positive bacteria secrete small
oligopeptides as their signal molecule
• The other bacteria have receptors for the signal
peptides (also called auto-inducers)
• When the receptor binds the signal peptide it
triggers the target genes
Gram Positive Quorum Sensing
ABC (ATP binding cassette) transporter
Recognizes GG containing sequence,
Cleaves
the peptide,
Final Peptide
Signaland secretes it
sensor kinase
- binding of autoinducer leads to
autophosphorylation at conserved
histidine residue
P
P
His
P
D
Precursor peptide
response regulator
- phosphorylation leads to
binding of regulator to
specific target promoters
GG
ACTTTGCGATTGGCC
Peptide signal
Precursor genes
How do you find what type of
signaling cyanobacteria use?
• Are they similar to the gram positive
bacteria?
• The gram negative?
• Or something entirely different?
Do Cyanobacteria use gram
negative type signaling?
• The LuxI protein in Vibrio fischeri has a
specific motif
• [LMFYA]-R-x(3)-F-x(2)-[KRQ]-x(2)-W-x[LIVM]-x(6,9)-E-x-D-x-[FY]-D
• Search proteins of cyanobacteria for this
motif = nil
Do Cyanobacteria use gram
negative type signaling?
• Use Pfam to find the sequence of proteins
related to Luxi
• Use conserved sequences to create a
PSSM to compare with cyanobacterial
proteins
Pfam search results for LuxI
Alignment of Conserved sequences for
autoinducer synthase
(LuxI like proteins)
Q9ZIU1_BURCE/10-189
Q9AM57_BURCE/10-189
Q9AM55_BURCE/10-189
Q9AM54_9BURK/10-189
Q93PD3_BURVI/10-173
Q93PF8_BURCE/10-173
Q9AER2_9BURK/10-189
Q9AM52_BURCE/10-189
Q9AM53_BURVI/10-189
Q93PF5_9BURK/10-173
Q9AM56_BURML/9-189
Q9AM45_BURML/9-189
Q9AM44_BURML/9-189
Q93NN9_BURML/9-189
Q9AM42_BURML/9-189
Q9AM43_BURML/9-189
Q8L2M9_BURPS/13-190
Q8KRT8_BURMA/10-190
Q6UBQ0_BURPS/10-190
Q6Q6F8_BURTH/10-190
SOLI1_RALSO/10-191
SOLI2_RALSO/10-191
Q9AHP8_BURCE/9-191
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-IHAHRA..G..PPK....q-V.DGRLV.VAC..
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-IHAHRA..G..PPK....q-V.DGRLV.VAC..
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-IHAHRA..G..PPK....q-V.DGRLV.VAC..
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-IHAHRA..G..PPK....q-V.DGRLV.VAC..
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-IHAHRA..G..PPK....q-V.DG---.---..
.NAEWAVRP..ML.AA.AVECAAQLGARQLIGVTFASMERLFRRIG-IHAHRA..G..PPK....q-V.DG---.---..
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.NAEWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.NADWAVRP..ML.AV.VVECAAQLGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.NADWAVRP..ML.AA.VVECAAQLGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DG---.---..
.GADWAVRP..ML.AA.VVACAAERGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.GADWAVRP..ML.AA.VVACAAERGARQLIGVTFASKERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.GADWAVRP..ML.AA.VVACAAERGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.GADWAVRP..ML.AA.VVACAAERGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.GADWAVRP..ML.AA.VVACAAERGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.GADWAVRP..ML.AA.VVACAAERGARQLIGVTFASMERLFRRIG-VHAHRA..G..PPK....q-V.DGRLV.VAC..
.NLAWAVRP..ML.AA.VVECAARLGAKQLIGVTFLSMERLFRRIG-VHAHRT..G..PAQ....q-I.DGRMV.VAC..
.GGNPAWAVrpML.AA.VVECAARLGAKQLIGVTFLSMERLFRRIG-VHAHRA..G..PAQ....q-I.DGRMV.VAC..
.GGNPAWAVrpML.AA.VVECAARLGAKQLIGVTFLSMERLFRRIG-VHAHRA..G..PAQ....q-I.DGRMV.VAC..
.TGNPAWAVrpML.AA.VVECAARLGARQLIGVTFLSMERLFRRIG-VHAHRA..G..PAQ....q-I.DGRMV.VAC..
.RPDWAVRP..ML.AS.VVQCAAQRGARRLIGVTFVSMVRLFRRIG-VRAHHA..G..PVR....c-I.GGRPV.VAC..
.RADWAVRP..ML.AS.VVQCAAQRGARRLIGATFVSMVRLFRRIG-VRAHRA..G..PVR....c-I.GGRPV.VAC..
.ESWQNTRA..MM.SE.IVRVAHAHGANRLIAFSVLGNERLLKRMG-VNVHRA..A..PPQ....m-I.EGKPT.LPF..
Comparison of s7942 protiens
against Luxi-PSSM
Results
Name of protein, starting position of sequence, sequence, score
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(#$S7942.p-Ser0724 (19 "LLQAASGLGAGLIVV" 1.1923437)
(208 "RLAHWLDRGYSQIAV" 3.6059587)
(#$S7942.p-Ser1616 (44 "AVLTAAPSSAAERIT" 1.884795)
(294
"HVTTSARSFENVLVG" 63.0499) (409 "VAAVAADGLASDVFG" 2.342644)
(431 "TVPTLIWGGSRDVVT" 16.80221)
(#$S7942.p-Ser2323 (65 "IRKWNRELDYRLIKE" 14.655321)
(77 "IKEVWAWHDNRIAVR" 3.8783476)
(#$S7942.p-Sef2443 (51 "TGKPAWELRTPQIVY" 14.529033)
(307 "SAKDQARLQANRLIW" 58.11094)
(#$S7942.p-Sef2642 (5 "WVRCARLLKLCFCTA" 8.126585)
(132 "VGEVAAERLTPAIAT" 7.601579)
(#$S7942.p-SSELR002 (146 "IVASSSLNGIQQVVK" 1160.4387)
(206 "NTAIAGGHGLTNSIT" 2.1221216) (229 "LIEYLVESGLPQDMA" 2.472199)
Do cyanobacteria use gram
positive type signaling
• The peptides used in gram positive
bacteria have a conserved GG leader
sequence which allows them to be
secreted by their ABC transporter
• This GG containing sequence has its own
motif as well LSX2ELX2IXGG
• Searching cyanobacteria for this motif = nil
Do cyanobacteria use gram
positive type signaling
• Possible GG containing sequences found
in other experiments
MRELTLTEIDNVSGA MKELTQTEVMEVSGA
TRELTENELEMTAGG FKELKENELTAITGG
MLELSNQELDYIAGG RQTLSDDELESVAGG
PVELSAEELDNVAGG MKELHTSELVEVSGG
MRELTSYELQAVSGG MRTINDVEMEEVSGG
VRELTVREIESVDGG MRELSKVEIEQISGA
MRELDREELNCVGGA LFINLSDEQQAFVAG
LLADLSTEQQQFLVG LLEDLSLDQQQSLAG
EQDTLSEAELESVAG
NEELSTDELKSVSGG
LKDLSEKELAAVFGG
RQTLSEDELESVAGG
MKELNDIEVTCVSGG
MRTINAAEMEEVSGG
MRTELEIHEIESIGGA
LFINLSDEQQAFVAG
LLVELSTEDQQNLAG
LQELSFDEIDQVSGA SQELSPQELANISGG IRELNEAELNCICGG
LQELTPEELEQIAGG LQELSTEELEQIAGG MQELSEEQLQATAGG
RQTLSDRELEGVAGG GRELSEEELESVAGG PIELSAEELDNVAGG
MIELQLHELKLVSGG MRELTSNEMNNVSGG MRELTSIEMNNVSGG
MRTLTLNELDSVSGG MRELAFQEIENVDGA MRELVIQEIESVDGG
MRKLSENEIKQISGG MREITESQLRYISGA MREISQKDLNLAFGA
LFMNLSDEQQAVVKG LFINLSDTQQAVVTG LFRNVSLEQQEMVVG
YLQDLSEQEQEIICG LFIDIYPEKSESVSG
LFTQISVEESGVAAG
Peptide signal molecules and bacteriocins in Gram-negative bacteria: a
genome-wide in silico screening for peptides containing a double-glycine
leader sequence and their cognate transporters
by
G. Dirixa, P. Monsieursb, B. Dombrechta, R. Danielsa, K. Marchalb,
J. Vanderleydena, J. Michielsa,.
Comparison of s7942 proteins
against GG-PSSM
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(#$S7942.p-Sef1302 1280.0376 MQHLVDGDLAANNGG)
(#$S7942.p-Ser0408 1193.9419 MEERMTVCNMAIEGG)
(#$S7942.p-Sef2007 39.282513 LGPEASSVIQSIAGG)
(#$S7942.p-Ser0406 24.167059 AEKMMQAAWQEISGG)
(#$S7942.p-Ser1379 40.601192 YEQLLAPIYEWMAGG)
(#$S7942.p-Sef0291 (28.36743 FLSLLSRDQVQWQGG)
(#$S7942.p-Ser0724 (2.1610742 RQVVVHRHLGAMLGG)
(122.12031 LRQLPLDALGLVFGG)
This protein comes from an unknown gene it is small
Like most Peptide signal molecules (less than 300 aa’s)
So it could be a likely candidate for an autoinducer
Do cyanobacteria communicate
with eachother?
• It would be beneficial for them to do so in
some cases
• Tricodesmium grows in clusters
• Fixes N2 But not with heterocysts
• Cells in middle of the clusters are
Surrounded by much less O2 than those
Outside the clusters
• Thus N2 fixation can occur in this
organism
Do cyanobacteria communicate
with each other?
• Cant give a definate answer based on
these results
• However there are sequences similar to
both types of Autoinducers present in the
proteins of cyanobacteria
What I would do differently
• Screen nucleotides instead of proteins
• Look for nearby ABC transporters for the
possible GG-hits
• Search more cyanobacteria for quorum
sensing systems
Thanks to colaborators
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Rakefet Schwarz Bar llan University
Alex from Bar llan university
Yitschak Friedman
Jeff Elhai VCU