The 25-kDa FK506-binding protein is localized in the nucleus and associates with casein kinase II and nucleolin.
AUTOR(ES)
Jin, Y J
RESUMO
FK506-binding proteins (FKBPs) have been identified as the cellular receptors of the immunosuppressive drugs FK506 and rapamycin. Recently, we cloned a 25-kDa FKBP family member (FKBP25) and found that FKBP25 contains a nuclear localization sequence and several potential casein kinase II phosphorylation sites. It has been previously shown that phosphorylation of proteins by casein kinase II can enhance their nuclear localization. Here we demonstrate that FKBP25 is localized to the nucleus and that a glutathione S-transferase fusion protein of FKBP25 (GST-FKBP25) can be phosphorylated by casein kinase II. Also a stable FKBP25/casein kinase II complex was formed when the GST-FKBP25 fusion protein was incubated either with purified casein kinase II or with cell lysates. Furthermore, when GST-FKBP25 was incubated with nuclear lysates, nucleolin, a major nuclear substrate of casein kinase II, was found associated with the GST-FKBP25/casein kinase II complex. Casein kinase II phosphorylation of several cytosolic and nuclear substrates, including nucleolin, appears to be important for the regulation of cell growth. The interaction of FKBP25 with casein kinase II may regulate these functions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=47224Documentos Relacionados
- The FK506-binding protein 25 functionally associates with histone deacetylases and with transcription factor YY1
- FKBP12, the 12-kDa FK506-binding protein, is a physiologic regulator of the cell cycle
- Phosphorylation of the immunosuppressant FK506-binding protein FKBP52 by casein kinase II: Regulation of HSP90-binding activity of FKBP52
- The FK506 binding protein 13 kDa (FKBP13) interacts with the C-chain of complement C1q
- Interaction of FK506-binding protein 13 with brefeldin A-inhibited guanine nucleotide-exchange protein 1 (BIG1): Effects of FK506