Proteasome 26S Subunit, Non ATPase 6 (PSMD6)

PSMD6, a highly conserved subunit of the 26S proteasome that exhibits similarity to the Arabidopsis fus6/cop11 family of signaling molecules. p44S10 gene copy number and mRNA expression were increased in association with segmental 1.8 - 11-fold chromosomal gains in cutaneous malignant melanoma cell lines and tumors. Likewise, malignant progression of human radial growth phase WM35 melanoma cells was associated with amplification and increased expression of endogenous p44S10, and increased expression of p44S10 was sufficient to induce proliferation of WM35 cells in vivo. The results demonstrate segmental copy number gains within chromosome 3p in cutaneous malignant melanoma and suggest that deregulation of a proteasome regulatory particle subunit may contribute to the malignant phenotype.