Characterization of cDNAs encoding p53 of Bombyx mori and Spodoptera frugiperda

Complementary DNAs encoding homologs of the tumor suppressor gene, p53, were characterized from two lepidopteran insects, Bombyx mori (Bm) and Spodoptera frugiperda (Sf). They encoded predicted proteins of 368 (41.2 kDa) (Bm) and 374 (42.5 kDa) (Sf) amino acids. The sequences shared 44% amino acid and 60% nucleotide sequence identity with each other, but exhibited less than 20% amino acid and 46% nucleotide sequence identity to Drosophila melanogaster p53. Despite the sequence diversity, conserved amino acids involved in DNA and zinc binding were present in the lepidopteran sequences. Expression of Sfp53-induced apoptosis in S. frugiperda cells, and antiserum made against recombinant Sfp53 recognized a protein whose abundance increased after treatment with DNA damaging agents.