Advanced

The molecular components of the extracellular protein-degradation pathways of the ectomycorrhizal fungus Paxillus involutus.

Shah, Firoz LU ; Rineau, Francois LU ; Canbäck, Björn LU ; Johansson, Tomas LU and Tunlid, Anders LU (2013) In New Phytologist 200(3). p.875-887
Abstract
Proteins contribute to a major part of the organic nitrogen (N) in forest soils. This N is mobilized and becomes available to trees as a result of the depolymerizing activities of symbiotic ectomycorrhizal fungi. The mechanisms by which these fungi depolymerize proteins and assimilate the released N are poorly characterized. Biochemical analysis and transcriptome profiling were performed to examine the proteolytic machinery and the uptake system of the ectomycorrhizal basidiomycete Paxillus involutus during the assimilation of organic N from various protein sources and extracts of organic matter. All substrates induced secretion of peptidase activity with an acidic pH optimum, mostly contributed by aspartic peptidases. The peptidase... (More)
Proteins contribute to a major part of the organic nitrogen (N) in forest soils. This N is mobilized and becomes available to trees as a result of the depolymerizing activities of symbiotic ectomycorrhizal fungi. The mechanisms by which these fungi depolymerize proteins and assimilate the released N are poorly characterized. Biochemical analysis and transcriptome profiling were performed to examine the proteolytic machinery and the uptake system of the ectomycorrhizal basidiomycete Paxillus involutus during the assimilation of organic N from various protein sources and extracts of organic matter. All substrates induced secretion of peptidase activity with an acidic pH optimum, mostly contributed by aspartic peptidases. The peptidase activity was transiently repressed by ammonium. Transcriptional analysis revealed a large number of extracellular endo- and exopeptidases. The expression levels of these peptidases were regulated in parallel with transporters and enzymes involved in the assimilation and metabolism of the released peptides and amino acids. For the first time the molecular components of the protein degradation pathways of an ectomycorrhizal fungus are described. The data suggest that the transcripts encoding these components are regulated in response to the chemical properties and the availability of the protein substrates. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ectomycorrhizal (ECM) fungi, nitrogen assimilation, nitrogen catabolite repression, nitrogen transporters, Paxillus involutus, peptidases, transcriptional regulation.
in
New Phytologist
volume
200
issue
3
pages
875 - 887
publisher
Wiley-Blackwell
external identifiers
  • wos:000325555400028
  • pmid:23902518
  • scopus:84885428443
ISSN
1469-8137
DOI
10.1111/nph.12425
project
BECC
language
English
LU publication?
yes
id
c942dc0d-0eb0-455c-8d07-10647d9a8c26 (old id 4006345)
date added to LUP
2013-09-25 12:47:07
date last changed
2019-10-16 01:17:57
@article{c942dc0d-0eb0-455c-8d07-10647d9a8c26,
  abstract     = {Proteins contribute to a major part of the organic nitrogen (N) in forest soils. This N is mobilized and becomes available to trees as a result of the depolymerizing activities of symbiotic ectomycorrhizal fungi. The mechanisms by which these fungi depolymerize proteins and assimilate the released N are poorly characterized. Biochemical analysis and transcriptome profiling were performed to examine the proteolytic machinery and the uptake system of the ectomycorrhizal basidiomycete Paxillus involutus during the assimilation of organic N from various protein sources and extracts of organic matter. All substrates induced secretion of peptidase activity with an acidic pH optimum, mostly contributed by aspartic peptidases. The peptidase activity was transiently repressed by ammonium. Transcriptional analysis revealed a large number of extracellular endo- and exopeptidases. The expression levels of these peptidases were regulated in parallel with transporters and enzymes involved in the assimilation and metabolism of the released peptides and amino acids. For the first time the molecular components of the protein degradation pathways of an ectomycorrhizal fungus are described. The data suggest that the transcripts encoding these components are regulated in response to the chemical properties and the availability of the protein substrates.},
  author       = {Shah, Firoz and Rineau, Francois and Canbäck, Björn and Johansson, Tomas and Tunlid, Anders},
  issn         = {1469-8137},
  keyword      = {ectomycorrhizal (ECM) fungi,nitrogen assimilation,nitrogen catabolite repression,nitrogen transporters,Paxillus involutus,peptidases,transcriptional regulation.},
  language     = {eng},
  number       = {3},
  pages        = {875--887},
  publisher    = {Wiley-Blackwell},
  series       = {New Phytologist},
  title        = {The molecular components of the extracellular protein-degradation pathways of the ectomycorrhizal fungus Paxillus involutus.},
  url          = {http://dx.doi.org/10.1111/nph.12425},
  volume       = {200},
  year         = {2013},
}