Applied Microbiology and Biotechnology

, Volume 92, Issue 6, pp 1197–1206

A carrier fusion significantly induces unfolded protein response in heterologous protein production by Aspergillus oryzae

  • Ayako Ohno
  • Jun-ichi Maruyama
  • Takashi Nemoto
  • Manabu Arioka
  • Katsuhiko Kitamoto
Applied genetics and molecular biotechnology

DOI: 10.1007/s00253-011-3487-9

Cite this article as:
Ohno, A., Maruyama, J., Nemoto, T. et al. Appl Microbiol Biotechnol (2011) 92: 1197. doi:10.1007/s00253-011-3487-9

Abstract

In heterologous protein production by filamentous fungi, target proteins are expressed as fusions with homologous secretory proteins, called carriers, for higher production yields. Although carrier fusion is thought to overcome the bottleneck in transcriptional and (post)translational processes during heterologous protein production, there is limited knowledge of its physiological effects on the host strain. In this study, we performed DNA microarray analysis by comparing gene expression patterns of two Aspergillus oryzae strains expressing either carrier- or non-carrier-fused bovine chymosin (CHY). When CHY was expressed as a fusion with α-amylase (AmyB), the production level increased by approximately 2-fold as compared with the non-carrier-fused CHY. DNA microarray analysis revealed that the carrier fusion significantly up-regulated many genes involved in endoplasmic reticulum (ER) protein-folding and secretion. Consistently, hacA transcripts were efficiently spliced in the strain expressing the carrier-fused CHY, indicating an unfolded protein response (UPR). The carrier-fused CHY was detected intracellularly without processing at the Kex2 cleavage site, which is likely recognized in the Golgi, and the carrier fusion delayed extracellular CHY production in the early growth phase as compared with the non-carrier-fused expression. Taken together, our data suggest a proposal that the carrier fusion temporarily accumulates the carrier-fused CHY in the ER and significantly induces UPR.

Keywords

Aspergillus oryzae Heterologous protein production Carrier UPR ER 

Supplementary material

253_2011_3487_MOESM1_ESM.pdf (316 kb)
ESM 1(PDF 316 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Ayako Ohno
    • 1
  • Jun-ichi Maruyama
    • 1
  • Takashi Nemoto
    • 1
  • Manabu Arioka
    • 1
  • Katsuhiko Kitamoto
    • 1
  1. 1.Department of BiotechnologyThe University of TokyoTokyoJapan

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