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

We report the isolation and sequencing of a 1326 bp cDNA fragment enco ding the cell-cycle proliferation protein ScPCNA from the flesh fly, S arcophaga crassipalpis. The amino acid (aa) sequence shows 91% and 79% identity to Drosophila melanogaster and Bombyx mori proliferating cel l nuclear antigen (PCNA), respectively. The coding sequence is interru pted by a single intron of 60 bp, resulting in a deduced aa sequence o f 260 residues. The gene is transcribed as a single mRNA (approx. 1.2 kb) as determined by Northern blot hybridization. Following a cold sho ck at -10 degrees C for 1 h, expression of ScPCNA decreased in S. cras sipalpis whole-body mRNA, suggesting a possible cell-cycle arrest in r esponse to a cold shock. One hour after removal from cold shock, ScPCN A 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. (C ) 1998 Elsevier Science B.V. All rights reserved.