Cloning and sequencing of proliferating cell nuclear antigen (PCNA) from the flesh fly, Sarcophaga crassipalpis, and its expression in response to cold shock and heat shock.

Abstract

We report the isolation and sequencing of a 1326<HSP SP = "0.25">bp cDNA fragment encoding the cell-cycle proliferation protein ScPCNA from the flesh fly, Sarcophaga crassipalpis. The amino acid (aa) sequence shows 91% and 79% identity to Drosophila melanogaster and Bombyx mori proliferating cell nuclear antigen (PCNA), respectively. The coding sequence is interrupted by a single intron of 60 bp, resulting in a deduced aa sequence of 260 residues. The gene is transcribed as a single mRNA (approx. 1.2 ) as determined by Northern blot hybridization. Following a cold shock at -10 degrees C for 1 h, expression of ScPCNA decreased in S. crassipalpis whole-body mRNA, suggesting a possible cell-cycle arrest in response to a cold shock. One hour after removal from cold shock, ScPCNA transcript levels were restored to the control level. By contrast, a 1 h heat shock at 45 degrees C did not alter expression of ScPCNA.