Characterization of secretory genes ypt1/yptA and nsf1/nsfA from two filamentous fungi: Induction of secretory pathway genes of Trichoderma reesei under secretion stress conditions

Markku Saloheimo, Huaming Wang, Mari Valkonen, Tuija Vasara, Anne Huuskonen, Marjukka Riikonen, Tiina Pakula, Michael Ward, Merja Penttilä

Research output: Contribution to journalArticleScientificpeer-review

26 Citations (Scopus)

Abstract

Two genes involved in protein secretion, encoding the Rab protein YPT1/YPTA and the general fusion factor NSFI/NSFA, were characterized from two filamentous fungi, Trichoderma reesei and Aspergillus niger var. awamori. The isolated genes showed a high level of conservation with their Saccharomyces cerevisiae and mammalian counterparts, and T. reesei ypt1 was shown to complement yeast Ypt1p depletion. The transcriptional regulation of the T. reesei ypt1, nsf1, and sar1 genes, involved in protein trafficking, was studied with mycelia treated with the folding inhibitor dithiothreitol (DTT) and with brefeldin A, which inhibits membrane traffic between the endoplasmic reticulum and Golgi complex. The well-known inducer of the yeast and T. reesei unfolded protein response (UPR), DTT, induced the nsf1 gene and the protein disulfide isomerase gene, pdi1, in both of the experiments, and sari mRNA increased in only one experiment under strong UPR induction. The ypt1 mRNA did not show a clear increase during DTT treatment. Brefeldin A strongly induced pdi1 and all of the intracellular trafficking genes studied. These results suggest the possibility that the whole secretory pathway of T. reesei could be induced at the transcriptional level by stress responses caused by protein accumulation in the secretory pathway.

Original languageEnglish
Pages (from-to)459-467
Number of pages9
JournalApplied and Environmental Microbiology
Volume70
Issue number1
DOIs
Publication statusPublished - Jan 2004
MoE publication typeA1 Journal article-refereed

Keywords

  • UNFOLDED PROTEIN RESPONSE
  • SENSITIVE FUSION PROTEIN
  • BREFELDIN-A
  • ENDOPLASMIC-RETICULUM
  • SACCHAROMYCES-CEREVISIAE
  • ASPERGILLUS-NIGER
  • MEMBRANE-FUSION
  • VESICULAR TRANSPORT
  • DISULFIDE-ISOMERASE
  • GOLGI

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