2007 Volume 76 Issue 3 Pages 3_137-3_143
Hsp90-Cdc37 chaperone complex facilitates the folding and activation of numerous protein kinases. In this report, we have isolated a cDNA clone coding for the Bombyx mori Cdc37 homologue, BmCdc37, and determined its nucleotide sequence. Its mRNA encodes a polypeptide of 373 amino acid residues, which shares 52% amino acid identity with Drosophila melanogaster Cdc37. RT-PCR analysis revealed that the expression of BmCDC37 mRNA occurred mainly in the testis. Direct interaction of the HA-tagged BmCdc37 with endogenous BmHsp90 was demonstrated by co-immunoprecipitation assay from the cell lysates. Subcellular localization site of HA-BmHsp90 and HA-BmCdc37 was exclusively cytoplasmic. However, anomalous nuclear localization of DsRed-BmHsp90, probably due to interaction with EGFP-fused BmCdc37, was re-adjusted to cytoplasmic localization by heat stress. These results suggested that BmCdc37 interacts with BmHsp90 in vivo and tends to be transported to cytoplasm by stress-induced cellular mechanisms.
