In vivo Visualization of the Distribution of a Secretory Protein in Aspergillus oryzae Hyphae Using the RntA-EGFP Fusion Protein

Abstract

  A fusion gene encoding ribonuclease T₁-EGFP (rntA-egfp) was constructed and expressed to use it as a tool for studies on the secretory pathway in Aspergillus oryzae. The successful secretion of the intact RntA-EGFP fusion protein was detected by fluorescence measurement and Western analysis. With use of the RntA-EGFP system, we were able to see high fluorescence at hyphal tips and observe concentrated fluorescence at septa in basal cells during growth at optimal conditions. Cold or heat shock during growth caused the accumulation of EGFP fluorescence in vacuoles.