| Modification Notes |
An extra copy of chromosome 21, the smallest human autosome chromosome, results in Down syndrome. The Down Syndrome critical region (DSCR) maps specifically to chromosme 21q22.2 and includes several genes which are likely associated with the pathogenesis of Down syndrome. DSCR 2 (down syndrome critical region protein 2), also known as Proteasome assembly chaperone 1, is a 288 amino acid protein that acts as a 20S proteasome-assembling chaperone and forms heterodimers with 20S proteasome precursors. Interestingly, DSCR 2 inhibits transcription of PPAR∫ and co-expression of these two proteins leads to the formation of DSCR 2 aggregates. With expression in adult colon, leukocytes, brain, testis and breast, DSCR 2 is localized to the endoplasmic reticulum and cytoplasm. There are two isoforms of DSCR 2 that exist as a result of alternative splicing events. |