Translational Regulation of Human Papillomavirus Type 16 E7 mRNA by the Peptide SEQIKA, Shared by Rabbit α(1)-Globin and Human Cytokeratin 7

The possible biochemical factors able to affect the in vitro expression of the high-risk human papillomavirus type 16 (HPV16) E7 oncoprotein have been analyzed. Evidence is provided that E7 mRNA stability is increased and, conversely, transcript translation is inhibited by binding to a 32-kDa protein from rabbit reticulocyte lysate; sequence analysis identified the 32-kDa binding protein as rabbit α(1)-globin protein; and interaction between rabbit α(1)-globin and E7 mRNA occurs through the 6-mer peptide SEQIKA present in human cytokeratin 7 protein. The in vitro data were confirmed by the occurrence of HPV16 E7 mRNA-cytokeratin 7 binding in squamous cervical cancer SiHa cells.