Studies on the Turtle Tumor Susceptibility Gene TSG101: Full-Length cDNA Sequence, Genomic Structural Analysis, and Role in Green Turtle Fibropapilloma

Abstract The tumor susceptibility gene TSG101 is a recently discovered gene whose functional knockout in mouse fibroblasts leads to transformation and tumor formation in nude mice. Human and mouse TSG101 cDNAs are 86% and 94% similar at the nucleotide and deduced amino acid levels, respectively. The highly conserved protein sequences suggest that the mouse and human TSG101 are true gene homologs that share fundamental biological functions. Here, we report that the turtle TSG101 full-length cDNA sequence contained a 1,176-base-pair open translational reading frame predicted to encode a 392-amino-acid protein. Alignment of TSG101 sequences showed that the turtle cDNA sequence was 82.3% and 84.4% similar to mouse and human TSG101, respectively, at the nucleotide level and 89.3% and 91.9% similar to mouse and human TSG101 proteins, respectively. A coiled-coil domain and a proline-rich region typical of the activation domain of transcription factors were highly conserved among the turtle, mouse, and human TSG1...