Biochem/physiol Actions QBP1 is an inhibitor of polyglutamine protein aggregation and cell death. QBP1 inhibits polyglutamine aggregation in COS-7 cells at a concentration of 25 μM, as shown by complete inhibition of thioredoxin-Q62 aggregation assayed by turbidity at 405 nm. QBP1 reduces cell death of these cells by 50% and increases median life span from 5.5-52 days in Drosophilla melanogaster that expresses the expanded polyglutamine; can be shortened to 8 amino acids (Trp-Ley-Trp-Trp-Pro-Gly-Ile-Phe) without the loss of ability to inhibit polyglutamine aggregation. Several inherited neurodegenerative diseases, Huntington′s dentatorubral pallidoluysian atrophy, spinobulbar muscular atrophy, and spinocerebellar ataxia are caused by the expanded CAG repeats in the coding region of the gene, leading to accumulation of polyglutamine. |
Biochem/physiol Actions QBP1 is an inhibitor of polyglutamine protein aggregation and cell death. QBP1 inhibits polyglutamine aggregation in COS-7 cells at a concentration of 25 μM, as shown by complete inhibition of thioredoxin-Q62 aggregation assayed by turbidity at 405 nm. QBP1 reduces cell death of these cells by 50% and increases median life span from 5.5-52 days in Drosophilla melanogaster that expresses the expanded polyglutamine; can be shortened to 8 amino acids (Trp-Ley-Trp-Trp-Pro-Gly-Ile-Phe) without the loss of ability to inhibit polyglutamine aggregation. Several inherited neurodegenerative diseases, Huntington′s dentatorubral pallidoluysian atrophy, spinobulbar muscular atrophy, and spinocerebellar ataxia are caused by the expanded CAG repeats in the coding region of the gene, leading to accumulation of polyglutamine. |