Cloning and characterization of the mouse tob gene.

The human Tob protein was identified as a molecule that interacted with the ErbB-2 protein, a receptor-type protein tyrosine kinase (RPTK). The interaction suggests that Tob is involved in RPTK-mediated signaling. In the present paper, we report molecular cloning and characterization of the mouse tob gene. The mouse tob gene contains an open reading frame of 1089 bp with 87% identity to its human counterpart in the nucleotide sequence. The coding region of mouse tob as well as human tob is not interrupted by introns. The mouse tob transcript is 2.3 kb long, the size being similar to that of the human tob transcript, and is detected ubiquitously in various tissues. Like human Tob, mouse Tob is characterized by the presence of a sequence rich in proline and glutamine which is often present in the sequence of transcription factors. In addition, the ATTTA motif characteristic of the immediate early gene is present in the 3'-untranslated region of the mouse tob gene. This, together with the conserved sequence and expression pattern of tob between mouse and human, suggests that Tob plays an important role in the response to extracellular signals.