---
_id: '803'
abstract:
- lang: eng
text: Eukaryotic cells store their chromosomes in a single nucleus. This is important
to maintain genomic integrity, as chromosomes packaged into separate nuclei (micronuclei)
are prone to massive DNA damage. During mitosis, higher eukaryotes disassemble
their nucleus and release individualized chromosomes for segregation. How numerous
chromosomes subsequently reform a single nucleus has remained unclear. Using image-based
screening of human cells, we identified barrier-to-autointegration factor (BAF)
as a key factor guiding membranes to form a single nucleus. Unexpectedly, nuclear
assembly does not require BAF?s association with inner nuclear membrane proteins
but instead relies on BAF?s ability to bridge distant DNA sites. Live-cell imaging
and in vitro reconstitution showed that BAF enriches around the mitotic chromosome
ensemble to induce a densely cross-bridged chromatin layer that is mechanically
stiff and limits membranes to the surface. Our study reveals that BAF-mediated
changes in chromosome mechanics underlie nuclear assembly with broad implications
for proper genome function.
acknowledged_ssus:
- _id: Bio
article_processing_charge: No
author:
- first_name: Matthias
full_name: Samwer, Matthias
last_name: Samwer
- first_name: Maximilian
full_name: Schneider, Maximilian
last_name: Schneider
- first_name: Rudolf
full_name: Hoefler, Rudolf
last_name: Hoefler
- first_name: Philipp S
full_name: Schmalhorst, Philipp S
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
- first_name: Julian
full_name: Jude, Julian
last_name: Jude
- first_name: Johannes
full_name: Zuber, Johannes
last_name: Zuber
- first_name: Daniel
full_name: Gerlic, Daniel
last_name: Gerlic
citation:
ama: Samwer M, Schneider M, Hoefler R, et al. DNA cross-bridging shapes a single
nucleus from a set of mitotic chromosomes. Cell. 2017;170(5):956-972. doi:10.1016/j.cell.2017.07.038
apa: Samwer, M., Schneider, M., Hoefler, R., Schmalhorst, P. S., Jude, J., Zuber,
J., & Gerlic, D. (2017). DNA cross-bridging shapes a single nucleus from a
set of mitotic chromosomes. Cell. Cell Press. https://doi.org/10.1016/j.cell.2017.07.038
chicago: Samwer, Matthias, Maximilian Schneider, Rudolf Hoefler, Philipp S Schmalhorst,
Julian Jude, Johannes Zuber, and Daniel Gerlic. “DNA Cross-Bridging Shapes a Single
Nucleus from a Set of Mitotic Chromosomes.” Cell. Cell Press, 2017. https://doi.org/10.1016/j.cell.2017.07.038.
ieee: M. Samwer et al., “DNA cross-bridging shapes a single nucleus from
a set of mitotic chromosomes,” Cell, vol. 170, no. 5. Cell Press, pp. 956–972,
2017.
ista: Samwer M, Schneider M, Hoefler R, Schmalhorst PS, Jude J, Zuber J, Gerlic
D. 2017. DNA cross-bridging shapes a single nucleus from a set of mitotic chromosomes.
Cell. 170(5), 956–972.
mla: Samwer, Matthias, et al. “DNA Cross-Bridging Shapes a Single Nucleus from a
Set of Mitotic Chromosomes.” Cell, vol. 170, no. 5, Cell Press, 2017, pp.
956–72, doi:10.1016/j.cell.2017.07.038.
short: M. Samwer, M. Schneider, R. Hoefler, P.S. Schmalhorst, J. Jude, J. Zuber,
D. Gerlic, Cell 170 (2017) 956–972.
date_created: 2018-12-11T11:48:35Z
date_published: 2017-08-24T00:00:00Z
date_updated: 2023-09-27T10:59:14Z
day: '24'
ddc:
- '570'
department:
- _id: CaHe
doi: 10.1016/j.cell.2017.07.038
external_id:
isi:
- '000408372400014'
file:
- access_level: open_access
checksum: 64897b0c5373f22273f598e4672c60ff
content_type: application/pdf
creator: dernst
date_created: 2019-01-18T13:45:40Z
date_updated: 2020-07-14T12:48:08Z
file_id: '5852'
file_name: 2017_Cell_Samwer.pdf
file_size: 17666637
relation: main_file
file_date_updated: 2020-07-14T12:48:08Z
has_accepted_license: '1'
intvolume: ' 170'
isi: 1
issue: '5'
language:
- iso: eng
month: '08'
oa: 1
oa_version: Published Version
page: 956 - 972
publication: Cell
publication_identifier:
issn:
- '00928674'
publication_status: published
publisher: Cell Press
publist_id: '6848'
quality_controlled: '1'
scopus_import: '1'
status: public
title: DNA cross-bridging shapes a single nucleus from a set of mitotic chromosomes
tmp:
image: /images/cc_by_nc_nd.png
legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode
name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
(CC BY-NC-ND 4.0)
short: CC BY-NC-ND (4.0)
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 170
year: '2017'
...
---
_id: '804'
abstract:
- lang: eng
text: Polysaccharides (carbohydrates) are key regulators of a large number of cell
biological processes. However, precise biochemical or genetic manipulation of
these often complex structures is laborious and hampers experimental structure–function
studies. Molecular Dynamics (MD) simulations provide a valuable alternative tool
to generate and test hypotheses on saccharide function. Yet, currently used MD
force fields often overestimate the aggregation propensity of polysaccharides,
affecting the usability of those simulations. Here we tested MARTINI, a popular
coarse-grained (CG) force field for biological macromolecules, for its ability
to accurately represent molecular forces between saccharides. To this end, we
calculated a thermodynamic solution property, the second virial coefficient of
the osmotic pressure (B22). Comparison with light scattering experiments revealed
a nonphysical aggregation of a prototypical polysaccharide in MARTINI, pointing
at an imbalance of the nonbonded solute–solute, solute–water, and water–water
interactions. This finding also applies to smaller oligosaccharides which were
all found to aggregate in simulations even at moderate concentrations, well below
their solubility limit. Finally, we explored the influence of the Lennard-Jones
(LJ) interaction between saccharide molecules and propose a simple scaling of
the LJ interaction strength that makes MARTINI more reliable for the simulation
of saccharides.
acknowledged_ssus:
- _id: ScienComp
acknowledgement: P.S.S. was supported by research fellowship 2811/1-1 from the German
Research Foundation (DFG), and M.S. was supported by EMBO Long Term Fellowship ALTF
187-2013 and Grant GC65-32 from the Interdisciplinary Centre for Mathematical and
Computational Modelling (ICM), University of Warsaw, Poland. The authors thank Antje
Potthast, Marek Cieplak, Tomasz Włodarski, and Damien Thompson for fruitful discussions
and the IST Austria Scientific Computing Facility for support.
article_processing_charge: No
author:
- first_name: Philipp S
full_name: Schmalhorst, Philipp S
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
- first_name: Felix
full_name: Deluweit, Felix
last_name: Deluweit
- first_name: Roger
full_name: Scherrers, Roger
last_name: Scherrers
- first_name: Carl-Philipp J
full_name: Heisenberg, Carl-Philipp J
id: 39427864-F248-11E8-B48F-1D18A9856A87
last_name: Heisenberg
orcid: 0000-0002-0912-4566
- first_name: Mateusz K
full_name: Sikora, Mateusz K
id: 2F74BCDE-F248-11E8-B48F-1D18A9856A87
last_name: Sikora
citation:
ama: Schmalhorst PS, Deluweit F, Scherrers R, Heisenberg C-PJ, Sikora MK. Overcoming
the limitations of the MARTINI force field in simulations of polysaccharides.
Journal of Chemical Theory and Computation. 2017;13(10):5039-5053. doi:10.1021/acs.jctc.7b00374
apa: Schmalhorst, P. S., Deluweit, F., Scherrers, R., Heisenberg, C.-P. J., &
Sikora, M. K. (2017). Overcoming the limitations of the MARTINI force field in
simulations of polysaccharides. Journal of Chemical Theory and Computation.
American Chemical Society. https://doi.org/10.1021/acs.jctc.7b00374
chicago: Schmalhorst, Philipp S, Felix Deluweit, Roger Scherrers, Carl-Philipp J
Heisenberg, and Mateusz K Sikora. “Overcoming the Limitations of the MARTINI Force
Field in Simulations of Polysaccharides.” Journal of Chemical Theory and Computation.
American Chemical Society, 2017. https://doi.org/10.1021/acs.jctc.7b00374.
ieee: P. S. Schmalhorst, F. Deluweit, R. Scherrers, C.-P. J. Heisenberg, and M.
K. Sikora, “Overcoming the limitations of the MARTINI force field in simulations
of polysaccharides,” Journal of Chemical Theory and Computation, vol. 13,
no. 10. American Chemical Society, pp. 5039–5053, 2017.
ista: Schmalhorst PS, Deluweit F, Scherrers R, Heisenberg C-PJ, Sikora MK. 2017.
Overcoming the limitations of the MARTINI force field in simulations of polysaccharides.
Journal of Chemical Theory and Computation. 13(10), 5039–5053.
mla: Schmalhorst, Philipp S., et al. “Overcoming the Limitations of the MARTINI
Force Field in Simulations of Polysaccharides.” Journal of Chemical Theory
and Computation, vol. 13, no. 10, American Chemical Society, 2017, pp. 5039–53,
doi:10.1021/acs.jctc.7b00374.
short: P.S. Schmalhorst, F. Deluweit, R. Scherrers, C.-P.J. Heisenberg, M.K. Sikora,
Journal of Chemical Theory and Computation 13 (2017) 5039–5053.
date_created: 2018-12-11T11:48:35Z
date_published: 2017-10-10T00:00:00Z
date_updated: 2023-09-27T10:58:45Z
day: '10'
department:
- _id: CaHe
doi: 10.1021/acs.jctc.7b00374
external_id:
isi:
- '000412965700036'
intvolume: ' 13'
isi: 1
issue: '10'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1704.03773
month: '10'
oa: 1
oa_version: Submitted Version
page: 5039 - 5053
publication: Journal of Chemical Theory and Computation
publication_identifier:
issn:
- '15499618'
publication_status: published
publisher: American Chemical Society
publist_id: '6847'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Overcoming the limitations of the MARTINI force field in simulations of polysaccharides
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 13
year: '2017'
...
---
_id: '802'
abstract:
- lang: eng
text: Glycoinositolphosphoceramides (GIPCs) are complex sphingolipids present at
the plasma membrane of various eukaryotes with the important exception of mammals.
In fungi, these glycosphingolipids commonly contain an alpha-mannose residue (Man)
linked at position 2 of the inositol. However, several pathogenic fungi additionally
synthesize zwitterionic GIPCs carrying an alpha-glucosamine residue (GlcN) at
this position. In the human pathogen Aspergillus fumigatus, the GlcNalpha1,2IPC
core (where IPC is inositolphosphoceramide) is elongated to Manalpha1,3Manalpha1,6GlcNalpha1,2IPC,
which is the most abundant GIPC synthesized by this fungus. In this study, we
identified an A. fumigatus N-acetylglucosaminyltransferase, named GntA, and demonstrate
its involvement in the initiation of zwitterionic GIPC biosynthesis. Targeted
deletion of the gene encoding GntA in A. fumigatus resulted in complete absence
of zwitterionic GIPC; a phenotype that could be reverted by episomal expression
of GntA in the mutant. The N-acetylhexosaminyltransferase activity of GntA was
substantiated by production of N-acetylhexosamine-IPC in the yeast Saccharomyces
cerevisiae upon GntA expression. Using an in vitro assay, GntA was furthermore
shown to use UDP-N-acetylglucosamine as donor substrate to generate a glycolipid
product resistant to saponification and to digestion by phosphatidylinositol-phospholipase
C as expected for GlcNAcalpha1,2IPC. Finally, as the enzymes involved in mannosylation
of IPC, GntA was localized to the Golgi apparatus, the site of IPC synthesis.
author:
- first_name: Jakob
full_name: Engel, Jakob
last_name: Engel
- first_name: Philipp S
full_name: Schmalhorst, Philipp S
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
- first_name: Anke
full_name: Kruger, Anke
last_name: Kruger
- first_name: Christina
full_name: Muller, Christina
last_name: Muller
- first_name: Falk
full_name: Buettner, Falk
last_name: Buettner
- first_name: Françoise
full_name: Routier, Françoise
last_name: Routier
citation:
ama: Engel J, Schmalhorst PS, Kruger A, Muller C, Buettner F, Routier F. Characterization
of an N-acetylglucosaminyltransferase involved in Aspergillus fumigatus zwitterionic
glycoinositolphosphoceramide biosynthesis. Glycobiology. 2015;25(12):1423-1430.
doi:10.1093/glycob/cwv059
apa: Engel, J., Schmalhorst, P. S., Kruger, A., Muller, C., Buettner, F., &
Routier, F. (2015). Characterization of an N-acetylglucosaminyltransferase involved
in Aspergillus fumigatus zwitterionic glycoinositolphosphoceramide biosynthesis.
Glycobiology. Oxford University Press. https://doi.org/10.1093/glycob/cwv059
chicago: Engel, Jakob, Philipp S Schmalhorst, Anke Kruger, Christina Muller, Falk
Buettner, and Françoise Routier. “Characterization of an N-Acetylglucosaminyltransferase
Involved in Aspergillus Fumigatus Zwitterionic Glycoinositolphosphoceramide Biosynthesis.”
Glycobiology. Oxford University Press, 2015. https://doi.org/10.1093/glycob/cwv059.
ieee: J. Engel, P. S. Schmalhorst, A. Kruger, C. Muller, F. Buettner, and F. Routier,
“Characterization of an N-acetylglucosaminyltransferase involved in Aspergillus
fumigatus zwitterionic glycoinositolphosphoceramide biosynthesis,” Glycobiology,
vol. 25, no. 12. Oxford University Press, pp. 1423–1430, 2015.
ista: Engel J, Schmalhorst PS, Kruger A, Muller C, Buettner F, Routier F. 2015.
Characterization of an N-acetylglucosaminyltransferase involved in Aspergillus
fumigatus zwitterionic glycoinositolphosphoceramide biosynthesis. Glycobiology.
25(12), 1423–1430.
mla: Engel, Jakob, et al. “Characterization of an N-Acetylglucosaminyltransferase
Involved in Aspergillus Fumigatus Zwitterionic Glycoinositolphosphoceramide Biosynthesis.”
Glycobiology, vol. 25, no. 12, Oxford University Press, 2015, pp. 1423–30,
doi:10.1093/glycob/cwv059.
short: J. Engel, P.S. Schmalhorst, A. Kruger, C. Muller, F. Buettner, F. Routier,
Glycobiology 25 (2015) 1423–1430.
date_created: 2018-12-11T11:48:35Z
date_published: 2015-12-01T00:00:00Z
date_updated: 2021-01-12T08:16:33Z
day: '01'
department:
- _id: CaHe
doi: 10.1093/glycob/cwv059
external_id:
pmid:
- '26306635'
intvolume: ' 25'
issue: '12'
language:
- iso: eng
month: '12'
oa_version: None
page: 1423 - 1430
pmid: 1
publication: Glycobiology
publication_status: published
publisher: Oxford University Press
publist_id: '6851'
quality_controlled: '1'
scopus_import: 1
status: public
title: Characterization of an N-acetylglucosaminyltransferase involved in Aspergillus
fumigatus zwitterionic glycoinositolphosphoceramide biosynthesis
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 25
year: '2015'
...
---
_id: '801'
abstract:
- lang: eng
text: Fungal cell walls frequently contain a polymer of mannose and galactose called
galactomannan. In the pathogenic filamentous fungus Aspergillus fumigatus, this
polysaccharide is made of a linear mannan backbone with side chains of galactofuran
and is anchored to the plasma membrane via a glycosylphosphatidylinositol or is
covalently linked to the cell wall. To date, the biosynthesis and significance
of this polysaccharide are unknown. The present data demonstrate that deletion
of the Golgi UDP-galactofuranose transporter GlfB or the GDP-mannose transporter
GmtA leads to the absence of galactofuran or galactomannan, respectively. This
indicates that the biosynthesis of galactomannan probably occurs in the lumen
of the Golgi apparatus and thus contrasts with the biosynthesis of other fungal
cell wall polysaccharides studied to date that takes place at the plasma membrane.
Transglycosylation of galactomannan from the membrane to the cell wall is hypothesized
because both the cell wall-bound and membrane-bound polysaccharide forms are affected
in the generated mutants. Considering the severe growth defect of the A. fumigatus
GmtA-deficient mutant, proving this paradigm might provide new targets for antifungal
therapy.
acknowledgement: This work was supported by the Deutsche Forschungsgemeinschaft.
article_processing_charge: No
article_type: original
author:
- first_name: Jakob
full_name: Engel, Jakob
last_name: Engel
- first_name: Philipp S
full_name: Schmalhorst, Philipp S
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
- first_name: Françoise
full_name: Routier, Françoise
last_name: Routier
citation:
ama: Engel J, Schmalhorst PS, Routier F. Biosynthesis of the fungal cell wall polysaccharide
galactomannan requires intraluminal GDP-mannose. Journal of Biological Chemistry.
2012;287(53):44418-44424. doi:10.1074/jbc.M112.398321
apa: Engel, J., Schmalhorst, P. S., & Routier, F. (2012). Biosynthesis of the
fungal cell wall polysaccharide galactomannan requires intraluminal GDP-mannose.
Journal of Biological Chemistry. American Society for Biochemistry and
Molecular Biology. https://doi.org/10.1074/jbc.M112.398321
chicago: Engel, Jakob, Philipp S Schmalhorst, and Françoise Routier. “Biosynthesis
of the Fungal Cell Wall Polysaccharide Galactomannan Requires Intraluminal GDP-Mannose.”
Journal of Biological Chemistry. American Society for Biochemistry and
Molecular Biology, 2012. https://doi.org/10.1074/jbc.M112.398321.
ieee: J. Engel, P. S. Schmalhorst, and F. Routier, “Biosynthesis of the fungal cell
wall polysaccharide galactomannan requires intraluminal GDP-mannose,” Journal
of Biological Chemistry, vol. 287, no. 53. American Society for Biochemistry
and Molecular Biology, pp. 44418–44424, 2012.
ista: Engel J, Schmalhorst PS, Routier F. 2012. Biosynthesis of the fungal cell
wall polysaccharide galactomannan requires intraluminal GDP-mannose. Journal of
Biological Chemistry. 287(53), 44418–44424.
mla: Engel, Jakob, et al. “Biosynthesis of the Fungal Cell Wall Polysaccharide Galactomannan
Requires Intraluminal GDP-Mannose.” Journal of Biological Chemistry, vol.
287, no. 53, American Society for Biochemistry and Molecular Biology, 2012, pp.
44418–24, doi:10.1074/jbc.M112.398321.
short: J. Engel, P.S. Schmalhorst, F. Routier, Journal of Biological Chemistry 287
(2012) 44418–44424.
date_created: 2018-12-11T11:48:34Z
date_published: 2012-12-28T00:00:00Z
date_updated: 2022-03-21T07:57:14Z
day: '28'
doi: 10.1074/jbc.M112.398321
extern: '1'
external_id:
pmid:
- '23139423'
intvolume: ' 287'
issue: '53'
language:
- iso: eng
month: '12'
oa_version: None
page: 44418 - 44424
pmid: 1
publication: Journal of Biological Chemistry
publication_status: published
publisher: American Society for Biochemistry and Molecular Biology
publist_id: '6852'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Biosynthesis of the fungal cell wall polysaccharide galactomannan requires
intraluminal GDP-mannose
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 287
year: '2012'
...
---
_id: '3292'
abstract:
- lang: eng
text: Galactofuranose (Galf) containing molecules have been described at the cell
surface of several eukaryotes and shown to contribute to the virulence of the
parasite Leishmania major and the fungus Aspergillus fumigatus. It is anticipated
that a number of the surface glycoconjugates such as N-glycans or glycolipids
are galactofuranosylated in the Golgi apparatus. This raises the question of how
the substrate for galactofuranosylation reactions, UDP-Galf, which is synthesized
in the cytosol, translocates into the organelles of the secretory pathway. Here
we report the first identification of a Golgi-localized nucleotide sugar transporter,
named GlfB, with specificity for a UDP-Galf. In vitro transport assays established
binding of UDP-Galf to GlfB and excluded transport of several other nucleotide
sugars. Furthermore, the implication of glfB in the galactofuranosylation of A.
fumigatus glycoconjugates and galactomannan was demonstrated by a targeted gene
deletion approach. Our data reveal a direct connection between galactomannan and
the organelles of the secretory pathway that strongly suggests that the cell wall-bound
polysaccharide originates from its glycosylphosphatidylinositol-anchored form.
author:
- first_name: Jakob
full_name: Engel, Jakob
last_name: Engel
- first_name: Philipp S
full_name: Schmalhorst, Philipp S
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
- first_name: Thilo
full_name: Dörk Bousset, Thilo
last_name: Dörk Bousset
- first_name: Vincent
full_name: Ferrières, Vincent
last_name: Ferrières
- first_name: Françoise
full_name: Routier, Françoise
last_name: Routier
citation:
ama: Engel J, Schmalhorst PS, Dörk Bousset T, Ferrières V, Routier F. A single UDP
galactofuranose transporter is required for galactofuranosylation in Aspergillus
fumigatus. Journal of Biological Chemistry. 2009;284(49):33859-33868. doi:10.1074/jbc.M109.070219
apa: Engel, J., Schmalhorst, P. S., Dörk Bousset, T., Ferrières, V., & Routier,
F. (2009). A single UDP galactofuranose transporter is required for galactofuranosylation
in Aspergillus fumigatus. Journal of Biological Chemistry. American Society
for Biochemistry and Molecular Biology. https://doi.org/10.1074/jbc.M109.070219
chicago: Engel, Jakob, Philipp S Schmalhorst, Thilo Dörk Bousset, Vincent Ferrières,
and Françoise Routier. “A Single UDP Galactofuranose Transporter Is Required for
Galactofuranosylation in Aspergillus Fumigatus.” Journal of Biological Chemistry.
American Society for Biochemistry and Molecular Biology, 2009. https://doi.org/10.1074/jbc.M109.070219 .
ieee: J. Engel, P. S. Schmalhorst, T. Dörk Bousset, V. Ferrières, and F. Routier,
“A single UDP galactofuranose transporter is required for galactofuranosylation
in Aspergillus fumigatus,” Journal of Biological Chemistry, vol. 284, no.
49. American Society for Biochemistry and Molecular Biology, pp. 33859–33868,
2009.
ista: Engel J, Schmalhorst PS, Dörk Bousset T, Ferrières V, Routier F. 2009. A single
UDP galactofuranose transporter is required for galactofuranosylation in Aspergillus
fumigatus. Journal of Biological Chemistry. 284(49), 33859–33868.
mla: Engel, Jakob, et al. “A Single UDP Galactofuranose Transporter Is Required
for Galactofuranosylation in Aspergillus Fumigatus.” Journal of Biological
Chemistry, vol. 284, no. 49, American Society for Biochemistry and Molecular
Biology, 2009, pp. 33859–68, doi:10.1074/jbc.M109.070219 .
short: J. Engel, P.S. Schmalhorst, T. Dörk Bousset, V. Ferrières, F. Routier, Journal
of Biological Chemistry 284 (2009) 33859–33868.
date_created: 2018-12-11T12:02:30Z
date_published: 2009-12-04T00:00:00Z
date_updated: 2021-01-12T07:42:26Z
day: '04'
doi: '10.1074/jbc.M109.070219 '
extern: '1'
intvolume: ' 284'
issue: '49'
language:
- iso: eng
month: '12'
oa_version: None
page: 33859 - 33868
publication: Journal of Biological Chemistry
publication_status: published
publisher: American Society for Biochemistry and Molecular Biology
publist_id: '3353'
quality_controlled: '1'
status: public
title: A single UDP galactofuranose transporter is required for galactofuranosylation
in Aspergillus fumigatus
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 284
year: '2009'
...
---
_id: '3400'
abstract:
- lang: eng
text: |-
Invasive fungal infections pose a serious threat to immunocompromised people. Most of these infections are caused by either Candida or Aspergillus species, with A. fumigatus being the predominant causative agent of Invasive Aspergillosis. Affected people comprise mainly haematopoietic stem cell or solid organ transplant patients who receive either high-dose corticosteroids or immunosuppressants. These risk factors predispose to the development of Invasive
Aspergillosis which is lethal in 20 to 80 % of the cases, largely due to insufficient efficacy of current antifungal therapy. Thus one major aim in current mycological research is the identification of new drug targets.
The polysaccharide-based fungal cell wall is both essential to fungi and absent from human cells which makes it appear an attractive new target. Notably, many components of the A. fumigatus cell wall, including the polysaccharide galactomannan, glycoproteins, and glycolipids, contain the unusual sugar galactofuranose (Galf). In contrast to the other cell wall monosaccharides, Galf does not occur on human cells but is known as component of cell surface molecules of many pathogenic bacteria and protozoa, such as Mycobacterium tuberculosis or Leishmania major. These molecules are often essential for virulence or viability of these organisms which suggested a possible role of Galf in the pathogenicity of A. fumigatus.
To address the importance of Galf in A. fumigatus, the key biosynthesis gene glfA, encoding UDPgalactopyranose mutase (UGM), was deleted. In different experimental approaches it was demonstrated that the absence of the glfA gene led to a complete loss of Galf-containing glycans.
Analysis of the DeltaglfA phenotype revealed growth and sporulation defects, reduced thermotolerance and an increased susceptibility to antifungal drugs. Electron Microscopy indicated a cell wall defect as a likely cause for the observed impairments. Furthermore, the virulence of the DeltaglfA mutant was found to be severely attenuated in a murine model of Invasive Aspergillosis.
The second focus of this study was laid on further elucidation of the galactofuranosylation pathway in A. fumigatus. In eukaryotes, a UDP-Galf transporter is likely required to transport UDP-Galf from the
cytosol into the organelles of the secretory pathway, but no such activity had been described. Sixteen candidate genes were identified in the A. fumigatus genome of which one, glfB, was found in close proximity to the glfA gene. In vitro transport assays revealed specificity of GlfB for UDP-Galf suggesting that glfB encoded indeed a UDP-Galf transporter. The influence of glfB on
galactofuranosylation was determined by a DeltaglfB deletion mutant, which closely recapitulated the DeltaglfA phenotype and was likewise found to be completely devoid of Galf. It could be concluded that all galactofuranosylation processes in A. fumigatus occur in the secretory pathway, including the biosynthesis of the cell wall polysaccharide galactomannan whose subcellular origin was previously disputed.
Thus in the course of this study the first UDP-Galf specific nucleotide sugar transporter was identified and its requirement for galactofuranosylation in A. fumigatus demonstrated. Moreover, it was shown that blocking the galactofuranosylation pathway impaired virulence of A. fumigatus which suggests the UDP-Galf biosynthesis enzyme UGM as a target for new antifungal drugs.
author:
- first_name: Philipp S
full_name: Philipp Schmalhorst
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
citation:
ama: Schmalhorst PS. Biosynthesis of Galactofuranose Containing Glycans and Their
Relevance for the Pathogenic Fungus Aspergillus fumigatus. 2009:1-72.
apa: Schmalhorst, P. S. (2009). Biosynthesis of Galactofuranose Containing Glycans
and Their Relevance for the Pathogenic Fungus Aspergillus fumigatus. Gottfried
Wilhelm Leibniz Universität Hannover.
chicago: Schmalhorst, Philipp S. “Biosynthesis of Galactofuranose Containing Glycans
and Their Relevance for the Pathogenic Fungus Aspergillus Fumigatus.” Gottfried
Wilhelm Leibniz Universität Hannover, 2009.
ieee: P. S. Schmalhorst, “Biosynthesis of Galactofuranose Containing Glycans and
Their Relevance for the Pathogenic Fungus Aspergillus fumigatus,” Gottfried Wilhelm
Leibniz Universität Hannover, 2009.
ista: Schmalhorst PS. 2009. Biosynthesis of Galactofuranose Containing Glycans and
Their Relevance for the Pathogenic Fungus Aspergillus fumigatus. Gottfried Wilhelm
Leibniz Universität Hannover.
mla: Schmalhorst, Philipp S. Biosynthesis of Galactofuranose Containing Glycans
and Their Relevance for the Pathogenic Fungus Aspergillus Fumigatus. Gottfried
Wilhelm Leibniz Universität Hannover, 2009, pp. 1–72.
short: P.S. Schmalhorst, Biosynthesis of Galactofuranose Containing Glycans and
Their Relevance for the Pathogenic Fungus Aspergillus Fumigatus, Gottfried Wilhelm
Leibniz Universität Hannover, 2009.
date_created: 2018-12-11T12:03:07Z
date_published: 2009-08-13T00:00:00Z
date_updated: 2021-01-12T07:43:13Z
day: '13'
extern: 1
main_file_link:
- open_access: '0'
url: http://edok01.tib.uni-hannover.de/edoks/e01dh09/609861891.pdf
month: '08'
page: 1 - 72
publication_status: published
publisher: Gottfried Wilhelm Leibniz Universität Hannover
publist_id: '3058'
quality_controlled: 0
status: public
title: Biosynthesis of Galactofuranose Containing Glycans and Their Relevance for
the Pathogenic Fungus Aspergillus fumigatus
type: dissertation
year: '2009'
...
---
_id: '3291'
abstract:
- lang: eng
text: 'The filamentous fungus Aspergillus fumigatus is responsible for a lethal
disease called Invasive Aspergillosis that affects immunocompromised patients.
This disease, like other human fungal diseases, is generally treated by compounds
targeting the primary fungal cell membrane sterol. Recently, glucan synthesis
inhibitors were added to the limited antifungal arsenal and encouraged the search
for novel targets in cell wall biosynthesis. Although galactomannan is a major
component of the A. fumigatus cell wall and extracellular matrix, the biosynthesis
and role of galactomannan are currently unknown. By a targeted gene deletion approach,
we demonstrate that UDP-galactopyranose mutase, a key enzyme of galactofuranose
metabolism, controls the biosynthesis of galactomannan and galactofuranose containing
glycoconjugates. The glfA deletion mutant generated in this study is devoid of
galactofuranose and displays attenuated virulence in a low-dose mouse model of
invasive aspergillosis that likely reflects the impaired growth of the mutant
at mammalian body temperature. Furthermore, the absence of galactofuranose results
in a thinner cell wall that correlates with an increased susceptibility to several
antifungal agents. The UDP-galactopyranose mutase thus appears to be an appealing
adjunct therapeutic target in combination with other drugs against A. fumigatus.
Its absence from mammalian cells indeed offers a considerable advantage to achieve
therapeutic selectivity. '
author:
- first_name: Philipp S
full_name: Philipp Schmalhorst
id: 309D50DA-F248-11E8-B48F-1D18A9856A87
last_name: Schmalhorst
orcid: 0000-0002-5795-0133
- first_name: Sven
full_name: Krappmann, Sven
last_name: Krappmann
- first_name: Wouter
full_name: Vervecken, Wouter
last_name: Vervecken
- first_name: Manfred
full_name: Rohde, Manfred
last_name: Rohde
- first_name: Meike
full_name: Müller, Meike
last_name: Müller
- first_name: Gerhard
full_name: Braus, Gerhard H.
last_name: Braus
- first_name: Roland
full_name: Contreras, Roland
last_name: Contreras
- first_name: Armin
full_name: Braun, Armin
last_name: Braun
- first_name: Hans
full_name: Bakker, Hans
last_name: Bakker
- first_name: Françoise
full_name: Routier, Françoise H
last_name: Routier
citation:
ama: Schmalhorst PS, Krappmann S, Vervecken W, et al. Contribution of galactofuranose
to the virulence of the opportunistic pathogen Aspergillus fumigatus. Eukaryotic
Cell. 2008;7(8):1268-1277. doi:10.1128/EC.00065-08
apa: Schmalhorst, P. S., Krappmann, S., Vervecken, W., Rohde, M., Müller, M., Braus,
G., … Routier, F. (2008). Contribution of galactofuranose to the virulence of
the opportunistic pathogen Aspergillus fumigatus. Eukaryotic Cell. American
Society for Microbiology. https://doi.org/10.1128/EC.00065-08
chicago: Schmalhorst, Philipp S, Sven Krappmann, Wouter Vervecken, Manfred Rohde,
Meike Müller, Gerhard Braus, Roland Contreras, Armin Braun, Hans Bakker, and Françoise
Routier. “Contribution of Galactofuranose to the Virulence of the Opportunistic
Pathogen Aspergillus Fumigatus.” Eukaryotic Cell. American Society for
Microbiology, 2008. https://doi.org/10.1128/EC.00065-08.
ieee: P. S. Schmalhorst et al., “Contribution of galactofuranose to the virulence
of the opportunistic pathogen Aspergillus fumigatus,” Eukaryotic Cell,
vol. 7, no. 8. American Society for Microbiology, pp. 1268–1277, 2008.
ista: Schmalhorst PS, Krappmann S, Vervecken W, Rohde M, Müller M, Braus G, Contreras
R, Braun A, Bakker H, Routier F. 2008. Contribution of galactofuranose to the
virulence of the opportunistic pathogen Aspergillus fumigatus. Eukaryotic Cell.
7(8), 1268–1277.
mla: Schmalhorst, Philipp S., et al. “Contribution of Galactofuranose to the Virulence
of the Opportunistic Pathogen Aspergillus Fumigatus.” Eukaryotic Cell,
vol. 7, no. 8, American Society for Microbiology, 2008, pp. 1268–77, doi:10.1128/EC.00065-08.
short: P.S. Schmalhorst, S. Krappmann, W. Vervecken, M. Rohde, M. Müller, G. Braus,
R. Contreras, A. Braun, H. Bakker, F. Routier, Eukaryotic Cell 7 (2008) 1268–1277.
date_created: 2018-12-11T12:02:29Z
date_published: 2008-06-13T00:00:00Z
date_updated: 2021-01-12T07:42:26Z
day: '13'
doi: 10.1128/EC.00065-08
extern: 1
intvolume: ' 7'
issue: '8'
month: '06'
page: 1268 - 1277
publication: Eukaryotic Cell
publication_status: published
publisher: American Society for Microbiology
publist_id: '3354'
quality_controlled: 0
status: public
title: Contribution of galactofuranose to the virulence of the opportunistic pathogen
Aspergillus fumigatus
type: journal_article
volume: 7
year: '2008'
...