---
_id: '14280'
abstract:
- lang: eng
text: "Cell division in Escherichia coli is performed by the divisome, a multi-protein
complex composed of more than 30 proteins. The divisome spans from the cytoplasm
through the inner membrane to the cell wall and the outer membrane. Divisome assembly
is initiated by a cytoskeletal structure, the so-called Z-ring, which localizes
at the center of the E. coli cell and determines the position of the future cell
septum. The Z-ring is composed of the highly conserved bacterial tubulin homologue
FtsZ, which forms treadmilling filaments. These filaments are recruited to the
inner membrane by FtsA, a highly conserved bacterial actin homologue. FtsA interacts
with other proteins in the periplasm and thus connects the cytoplasmic and periplasmic
components of the divisome. \r\nA previous model postulated that FtsA regulates
maturation of the divisome by switching from an oligomeric, inactive state to
a monomeric and active state. This model was based mostly on in vivo studies,
as a biochemical characterization of FtsA has been hampered by difficulties in
purifying the protein. Here, we studied FtsA using an in vitro reconstitution
approach and aimed to answer two questions: (i) How are dynamics from cytoplasmic,
treadmilling FtsZ filaments coupled to proteins acting in the periplasmic space
and (ii) How does FtsA regulate the maturation of the divisome?\r\nWe found that
the cytoplasmic peptides of the transmembrane proteins FtsN and FtsQ interact
directly with FtsA and can follow the spatiotemporal signal of FtsA/Z filaments.
When we investigated the underlying mechanism by imaging single molecules of FtsNcyto,
we found the peptide to interact transiently with FtsA. An in depth analysis of
the single molecule trajectories helped to postulate a model where PG synthases
follow the dynamics of FtsZ by a diffusion and capture mechanism. \r\nFollowing
up on these findings we were interested in how the self-interaction of FtsA changes
when it encounters FtsNcyto and if we can confirm the proposed oligomer-monomer
switch. For this, we compared the behavior of the previously identified, hyperactive
mutant FtsA R286W with wildtype FtsA. The mutant outperforms WT in mirroring and
transmitting the spatiotemporal signal of treadmilling FtsZ filaments. Surprisingly
however, we found that this was not due to a difference in the self-interaction
strength of the two variants, but a difference in their membrane residence time.
Furthermore, in contrast to our expectations, upon binding of FtsNcyto the measured
self-interaction of FtsA actually increased. \r\nWe propose that FtsNcyto induces
a rearrangement of the oligomeric architecture of FtsA. In further consequence
this change leads to more persistent FtsZ filaments which results in a defined
signalling zone, allowing formation of the mature divisome. The observed difference
between FtsA WT and R286W is due to the vastly different membrane turnover of
the proteins. R286W cycles 5-10x faster compared to WT which allows to sample
FtsZ filaments at faster frequencies. These findings can explain the observed
differences in toxicity for overexpression of FtsA WT and R286W and help to understand
how FtsA regulates divisome maturation."
acknowledged_ssus:
- _id: Bio
- _id: LifeSc
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Philipp
full_name: Radler, Philipp
id: 40136C2A-F248-11E8-B48F-1D18A9856A87
last_name: Radler
orcid: '0000-0001-9198-2182 '
citation:
ama: Radler P. Spatiotemporal signaling during assembly of the bacterial divisome.
2023. doi:10.15479/at:ista:14280
apa: Radler, P. (2023). Spatiotemporal signaling during assembly of the bacterial
divisome. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:14280
chicago: Radler, Philipp. “Spatiotemporal Signaling during Assembly of the Bacterial
Divisome.” Institute of Science and Technology Austria, 2023. https://doi.org/10.15479/at:ista:14280.
ieee: P. Radler, “Spatiotemporal signaling during assembly of the bacterial divisome,”
Institute of Science and Technology Austria, 2023.
ista: Radler P. 2023. Spatiotemporal signaling during assembly of the bacterial
divisome. Institute of Science and Technology Austria.
mla: Radler, Philipp. Spatiotemporal Signaling during Assembly of the Bacterial
Divisome. Institute of Science and Technology Austria, 2023, doi:10.15479/at:ista:14280.
short: P. Radler, Spatiotemporal Signaling during Assembly of the Bacterial Divisome,
Institute of Science and Technology Austria, 2023.
date_created: 2023-09-06T10:58:25Z
date_published: 2023-09-25T00:00:00Z
date_updated: 2024-02-21T12:35:18Z
day: '25'
ddc:
- '572'
degree_awarded: PhD
department:
- _id: GradSch
- _id: MaLo
doi: 10.15479/at:ista:14280
ec_funded: 1
file:
- access_level: closed
checksum: 87eef11fbc5c7df0826f12a3a629b444
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: pradler
date_created: 2023-10-04T10:11:53Z
date_updated: 2023-10-04T10:28:35Z
file_id: '14390'
file_name: PhD Thesis_Philipp Radler_20231004.docx
file_size: 114932847
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content_type: application/pdf
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date_created: 2023-10-04T10:11:21Z
date_updated: 2023-10-04T10:28:35Z
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file_size: 37838778
relation: main_file
file_date_updated: 2023-10-04T10:28:35Z
has_accepted_license: '1'
keyword:
- Cell Division
- Reconstitution
- FtsZ
- FtsA
- Divisome
- E.coli
language:
- iso: eng
month: '09'
oa_version: Published Version
page: '156'
project:
- _id: 2595697A-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '679239'
name: Self-Organization of the Bacterial Cell
- _id: fc38323b-9c52-11eb-aca3-ff8afb4a011d
grant_number: P34607
name: "Understanding bacterial cell division by in vitro\r\nreconstitution"
- _id: 2596EAB6-B435-11E9-9278-68D0E5697425
grant_number: ALTF 2015-1163
name: Synthesis of bacterial cell wall
- _id: 259B655A-B435-11E9-9278-68D0E5697425
grant_number: LT000824/2016
name: Reconstitution of bacterial cell wall sythesis
publication_identifier:
isbn:
- 978-3-99078-033-6
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '11373'
relation: part_of_dissertation
status: public
- id: '7387'
relation: part_of_dissertation
status: public
- id: '10934'
relation: research_data
status: public
status: public
supervisor:
- first_name: Martin
full_name: Loose, Martin
id: 462D4284-F248-11E8-B48F-1D18A9856A87
last_name: Loose
orcid: 0000-0001-7309-9724
title: Spatiotemporal signaling during assembly of the bacterial divisome
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
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type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '5587'
abstract:
- lang: eng
text: "Supporting material to the article \r\nSTATISTICAL MECHANICS FOR METABOLIC
NETWORKS IN STEADY-STATE GROWTH\r\n\r\nboundscoli.dat\r\nFlux Bounds of the E.
coli catabolic core model iAF1260 in a glucose limited minimal medium. \r\n\r\npolcoli.dat\r\nMatrix
enconding the polytope of the E. coli catabolic core model iAF1260 in a glucose
limited minimal medium, \r\nobtained from the soichiometric matrix by standard
linear algebra (reduced row echelon form).\r\n\r\nellis.dat\r\nApproximate Lowner-John
ellipsoid rounding the polytope of the E. coli catabolic core model iAF1260 in
a glucose limited minimal medium\r\nobtained with the Lovasz method.\r\n\r\npoint0.dat\r\nCenter
of the approximate Lowner-John ellipsoid rounding the polytope of the E. coli
catabolic core model iAF1260 in a glucose limited minimal medium\r\nobtained with
the Lovasz method.\r\n\r\nlovasz.cpp \r\nThis c++ code file receives in input
the polytope of the feasible steady states of a metabolic network, \r\n(matrix
and bounds), and it gives in output an approximate Lowner-John ellipsoid rounding
the polytope\r\nwith the Lovasz method \r\nNB inputs are referred by defaults
to the catabolic core of the E.Coli network iAF1260. \r\nFor further details we
refer to PLoS ONE 10.4 e0122670 (2015).\r\n\r\nsampleHRnew.cpp \r\nThis c++
code file receives in input the polytope of the feasible steady states of a metabolic
network, \r\n(matrix and bounds), the ellipsoid rounding the polytope, a point
inside and \r\nit gives in output a max entropy sampling at fixed average growth
rate \r\nof the steady states by performing an Hit-and-Run Monte Carlo Markov
chain.\r\nNB inputs are referred by defaults to the catabolic core of the E.Coli
network iAF1260. \r\nFor further details we refer to PLoS ONE 10.4 e0122670 (2015)."
article_processing_charge: No
author:
- first_name: Daniele
full_name: De Martino, Daniele
id: 3FF5848A-F248-11E8-B48F-1D18A9856A87
last_name: De Martino
orcid: 0000-0002-5214-4706
- first_name: Gasper
full_name: Tkacik, Gasper
id: 3D494DCA-F248-11E8-B48F-1D18A9856A87
last_name: Tkacik
orcid: 0000-0002-6699-1455
citation:
ama: De Martino D, Tkačik G. Supporting materials “STATISTICAL MECHANICS FOR METABOLIC
NETWORKS IN STEADY-STATE GROWTH.” 2018. doi:10.15479/AT:ISTA:62
apa: De Martino, D., & Tkačik, G. (2018). Supporting materials “STATISTICAL
MECHANICS FOR METABOLIC NETWORKS IN STEADY-STATE GROWTH.” Institute of Science
and Technology Austria. https://doi.org/10.15479/AT:ISTA:62
chicago: De Martino, Daniele, and Gašper Tkačik. “Supporting Materials ‘STATISTICAL
MECHANICS FOR METABOLIC NETWORKS IN STEADY-STATE GROWTH.’” Institute of Science
and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:62.
ieee: D. De Martino and G. Tkačik, “Supporting materials ‘STATISTICAL MECHANICS
FOR METABOLIC NETWORKS IN STEADY-STATE GROWTH.’” Institute of Science and Technology
Austria, 2018.
ista: De Martino D, Tkačik G. 2018. Supporting materials ‘STATISTICAL MECHANICS
FOR METABOLIC NETWORKS IN STEADY-STATE GROWTH’, Institute of Science and Technology
Austria, 10.15479/AT:ISTA:62.
mla: De Martino, Daniele, and Gašper Tkačik. Supporting Materials “STATISTICAL
MECHANICS FOR METABOLIC NETWORKS IN STEADY-STATE GROWTH.” Institute of Science
and Technology Austria, 2018, doi:10.15479/AT:ISTA:62.
short: D. De Martino, G. Tkačik, (2018).
datarep_id: '111'
date_created: 2018-12-12T12:31:41Z
date_published: 2018-09-21T00:00:00Z
date_updated: 2024-02-21T13:45:39Z
day: '21'
ddc:
- '530'
department:
- _id: GaTk
doi: 10.15479/AT:ISTA:62
ec_funded: 1
file:
- access_level: open_access
checksum: 97992e3e8cf8544ec985a48971708726
content_type: application/zip
creator: system
date_created: 2018-12-12T13:05:13Z
date_updated: 2020-07-14T12:47:08Z
file_id: '5641'
file_name: IST-2018-111-v1+1_CODES.zip
file_size: 14376
relation: main_file
file_date_updated: 2020-07-14T12:47:08Z
has_accepted_license: '1'
keyword:
- metabolic networks
- e.coli core
- maximum entropy
- monte carlo markov chain sampling
- ellipsoidal rounding
license: https://creativecommons.org/publicdomain/zero/1.0/
month: '09'
oa: 1
oa_version: Published Version
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '291734'
name: International IST Postdoc Fellowship Programme
- _id: 254E9036-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: P28844-B27
name: Biophysics of information processing in gene regulation
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '161'
relation: research_paper
status: public
status: public
title: Supporting materials "STATISTICAL MECHANICS FOR METABOLIC NETWORKS IN STEADY-STATE
GROWTH"
tmp:
image: /images/cc_0.png
legal_code_url: https://creativecommons.org/publicdomain/zero/1.0/legalcode
name: Creative Commons Public Domain Dedication (CC0 1.0)
short: CC0 (1.0)
type: research_data
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2018'
...