Heat shock protein 80 of Neurospora crassa: Sequence analysis of the gene and expression during the asexual phase

Heat shock protein 80 (Hsp80) of Neurospora crassa, a member of the stress- 90 protein family, is a cytosolic molecular chaperone that interacts direct ly with Hsp70 to form a hetero-oligomeric complex. The complete nucleotide sequence of the gene encoding this protein, along with the 5'- and 3'-flank ing DNA, is reported. The coding sequence is interrupted by two introns, 61 and 30 nucleotides, respectively, in length. The deduced amino acid sequen ce corresponds to a 695-residue polypeptide with a calculated molecular mas s of 78 894 Da and an average pI of 4.94. Primer extension experiments demo nstrated two transcription start sites, a major and a minor one. No sequenc e motifs resembling the standard eukaryotic heat shock elements were eviden t in the putative promoter region. Immunoblot analysis showed Hsp80 protein to be present in the mature, dormant conidia, while the hsp80 transcripts were not detected. Both the transcripts and the protein were present in the germinating conidia in the absence of externally applied stress.