Show legend Show as text

Structure type: structural motif or average structure
Aglycon: (->4) Asn-X-Ser/Thr (protein)
Compound class: N-glycan
Contained glycoepitopes: IEDB_123886,IEDB_130701,IEDB_135813,IEDB_136104,IEDB_137340,IEDB_137485,IEDB_1394182,IEDB_140116,IEDB_140942,IEDB_141793,IEDB_141807,IEDB_141828,IEDB_141829,IEDB_141830,IEDB_141831,IEDB_143632,IEDB_144983,IEDB_144996,IEDB_151079,IEDB_151531,IEDB_152206,IEDB_153212,IEDB_153220,IEDB_164046,IEDB_164174,IEDB_187201,IEDB_187238,IEDB_187239,IEDB_187240,IEDB_429156,IEDB_474450,IEDB_540671,IEDB_548907,IEDB_857734,IEDB_857735,IEDB_983930,SB_136,SB_191,SB_196,SB_197,SB_198,SB_33,SB_44,SB_53,SB_67,SB_72,SB_73,SB_74,SB_77,SB_85

• Article ID: 7895
  Aguiar TQ, Maaheimo H, Heiskanen A, Wiebe MG, Merja Penttilä M, Domingues L "Characterization of the Ashbya gossypii secreted N-glycome and genomic insights into its N-glycosylation pathway" - Carbohydrate Research 381 (2013) 19-27
  

  The riboflavin producer Ashbya gossypii is a filamentous hemiascomycete, closely related to the yeast Saccharomyces cerevisiae, that has been used as a model organism to study fungal developmental biology. It has also been explored as a host for the expression of recombinant proteins. However, although N-glycosylation plays important roles in protein secretion, morphogenesis, and the development of multicellular organisms, the N-glycan structures synthesised by A. gossypii had not been elucidated. In this study, we report the first characterization of A. gossypii N-glycans and provide valuable insights into their biosynthetic pathway. By combined matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry profiling and nuclear magnetic resonance (NMR) spectroscopy we determined that the A. gossypii secreted N-glycome is characterized by high-mannose type structures in the range Man4–18GlcNAc2, mostly containing neutral core-type N-glycans with 8–10 mannoses. Cultivation in defined minimal media induced the production of acidic mannosylphosphorylated N-glycans, generally more elongated than the neutral N-glycans. Truncated neutral N-glycan structures similar to those found in other filamentous fungi (Man4–7GlcNAc2) were detected, suggesting the possible existence of trimming activity in A. gossypii. Homologs for all of the S. cerevisiae genes known to be involved in the endoplasmatic reticulum and Golgi N-glycan processing were found in the A. gossypii genome. However, processing of N-glycans by A. gossypii differs considerably from that by S. cerevisiae, allowing much shorter N-glycans. Genes for two putative N-glycan processing enzymes were identified, that did not have homologs in S. cerevisiae.

  N-glycosylation, Ashbya gossypii, N-glycan structure, secreted glycoproteins

  NCBI PubMed ID: 24056010
  Publication DOI: 10.1016/j.carres.2013.08.015
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: Domingues L
  Institutions: IBB–Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, Braga, Portugal, VTT Technical Research Centre of Finland, Finland, Glykos Finland Ltd, Helsinki, Finland
  Methods: 1H NMR, MALDI-TOF, TOCSY, DQF-COSY, HSQC
  
   
  
  Ashbya gossypii ATCC 10895
  CSDB ID 44833 (all data & tools)

Show legend Show as text

Structure type: monomer
Trivial name: riboflavin, vitamin B2
Compound class: glycoside
Contained glycoepitopes: IEDB_114703,IEDB_161730

• Article ID: 8895
  Silva R, Aguiar TQ, Oliveira C, Domingues L "Physiological characterization of a pyrimidine auxotroph exposes link between uracil phosphoribosyltransferase regulation and riboflavin production in Ashbya gossypii" - New Biotechnology 50 (2019) 1-8
  

  The blockage of the de novo pyrimidine biosynthetic pathway at the orotidine-5'-phosphate decarboxylase level was previously demonstrated to affect riboflavin production in the industrial producer fungus Ashbya gossypii. However, the molecular basis for the unusual sensitivity to uracil displayed by the pyrimidine auxotroph A. gossypii Agura3 was unknown. Here, uridine was shown to be the only intermediate of the pyrimidine salvage pathway able to fully restore this mutant's growth. Conversely, uracil, which is routinely used to rescue pyrimidine auxotrophs, had a dose-dependent growth-inhibitory effect. Uracil phosphoribosyltransferase (UPRT) is the pyrimidine salvage pathway enzyme responsible for converting uracil to uridine monophosphate in the presence of phosphoribosyl pyrophosphate (PRPP). Characterization of the A. gossypii UPRT, as produced and purified from Escherichia coli, revealed that uracil concentrations above 1 mM negatively affected its activity, thus explaining the hypersensitivity of the Agura3 mutant to uracil. Accordingly, overexpression of the AgUPRT encoding-gene in A. gossypii Agura3 led to similar growth on rich medium containing 5 mM uracil or uridine. Decreased UPRT activity ultimately favors the preservation of PRPP, which otherwise may be directed to other pathways. In A. gossypii, increased PRPP availability promotes overproduction of riboflavin. Thus, this UPRT modulation mechanism reveals a putative means of saving precursors essential for riboflavin overproduction by this fungus. A similar uracil-mediated regulation mechanism of the UPRT activity is reported only in two protozoan parasites, whose survival depends on the availability of PRPP. Physiological evidence here discussed indicate that it may be extended to other distantly related flavinogenic fungi.

  Ashbya gossypii, auxotrophy, phosphoribosyltransferase, pyrimidine metabolism, riboflavin production, uracil, uracil/uridine

  NCBI PubMed ID: 30590201
  Publication DOI: 10.1016/j.nbt.2018.12.004
  Journal NLM ID: 101465345
  Publisher: Amsterdam: Elsevier
  Correspondence: Domingues L
  Institutions: CEB – Centre of Biological Engineering, University of Minho, Braga, Portugal
  
   
  
  Ashbya gossypii ATCC 10895
  CSDB ID 49669 (all data & tools)