Cloning and characterization of the bipA gene encoding ER chaperone BiP from Aspergillus oryzae

We describe the cloning and characterization of the ER localized chaperone (BiP) encoding gene from the filamentous fungus Aspergillus oryzae. The BiP encoding gene, designated bipA, has three introns and encodes a protein with 672 amino acids, which has a high homology with various BiP-like proteins. Sequences resembling heat shock elements (HSEs) and unfolded protein response (UPR) elements, as found in the Saccharomyces cerevisiae KAR2 promoter, are present in the 5' no coding region of the bipA gene. Transcription of the bipA gene was increased by heat shock or tunicamycin treatment. Expression of bipA cDNA partially complemented the temperature-sensitive growth of kar2 mutant alleles of S. cerevisiae. These results indicate that the bipA gene product plays a role as BiP in A. oryzae.