TETRASPANIN 33; TSPAN33

Alternative titles; symbols

• PENUMBRA; PEN

HGNC Approved Gene Symbol: TSPAN33

Cytogenetic location: 7q32.1 Genomic coordinates (GRCh38): 7:129,144,706-129,169,698 (from NCBI)

▼ Cloning and Expression
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.

▼ Gene Function
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.

▼ Gene Structure
Chen et al. (2005) determined that the TSPAN33 gene contains 9 exons and spans approximately 25 kb.

▼ Mapping
By sequence analysis and FISH, Chen et al. (2005) mapped the TSPAN33 gene to chromosome 7q32.1, a region that is a hotspot for cytogenetic abnormalities in myeloid malignancies.

▼ Cytogenetics
Using FISH with a mixture of 4 TSPAN33 genomic clones, Chen et al. (2005) analyzed 7 cases of myeloid malignancies with 7q deletions and determined that 5 patients with cytogenetic deletions involving 7q31.2-q32 also had TSPAN33 gene deletions. The other 2 patients had deletions outside the 7q31.2-q32 region.