Retinoblastoma protein co-purifies with proteasomal insulin-degrading enzyme: implications for cell proliferation control.
Biochem Biophys Res Commun
; 395(2): 196-9, 2010 Apr 30.
Article
em En
| MEDLINE
| ID: mdl-20362553
ABSTRACT
Previous investigations on proteasomal preparations containing insulin-degrading enzyme (IDE; EC 3.4.24.56) have invariably yielded a co-purifying protein with a molecular weight of about 110kDa. We have now found both in MCF-7 breast cancer and HepG2 hepatoma cells that this associated molecule is the retinoblastoma tumor suppressor protein (RB). Interestingly, the amount of RB in this protein complex seemed to be lower in HepG2 vs. MCF-7 cells, indicating a higher (cytoplasmic) protein turnover in the former vs. the latter cells. Moreover, immunofluorescence showed increased nuclear localization of RB in HepG2 vs. MCF-7 cells. Beyond these subtle differences between these distinct tumor cell types, our present study more generally suggests an interplay between RB and IDE within the proteasome that may have important growth-regulatory consequences.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteína do Retinoblastoma
/
Complexo de Endopeptidases do Proteassoma
/
Proliferação de Células
/
Insulisina
Limite:
Humans
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article