Tetraspanin 33 (TSPAN33)

The mouse Tspan33 (Penumbra) gene was cloned based on its differential expression in proerythroblasts/erythroblasts (Pasquini et al., 2003). Using the mouse Tspan33 sequence as a probe, Pasquini et al. (2003) cloned a human TSPAN33 cDNA from a bone marrow cDNA library. The deduced 283-amino acid protein shares 97% sequence identity with the mouse ortholog.

Using transfection experiments in mouse erythroleukemia (MEL) cells, Pasquini et al. (2003) found that Tspan33 exhibited growth-suppressive activity. Expression of siRNA targeted to the Tspan33 cDNA appeared to decrease the clonal growth of MEL cells.Chen et al. (2005) determined that the TSPAN33 gene contains 9 exons and spans approximately 25 kb.