Phosducin (Pdc), a highly conserved phosphoprotein, plays an important role in the regulation of G protein signaling, transcriptional control, and modulation of blood pressure. Pdc is negatively regulated by phosphorylation followed by binding to the 14-3-3 protein, whose role is still unclear. To gain insight into the role of 14-3-3 in the regulation of Pdc function, we studied structural changes of Pdc induced by phosphorylation and 14-3-3 protein binding using time-resolved fluorescence spectroscopy. Our data show that the phosphorylation of the N-terminal domain of Pdc at Ser-54 and Ser-73 affects the structure of the whole Pdc molecule. Complex formation with 14-3-3 reduces the flexibility of both the N- and C-terminal domains of phosphorylated Pdc, as determined by time-resolved tryptophan and dansyl fluorescence. Therefore, our data suggest that phosphorylated Pdc undergoes a conformational change when binding to 14-3-3. These changes involve the G(t)βγ binding surface within the N-terminal domain of Pdc, and thus could explain the inhibitory effect of 14-3-3 on Pdc function.

• MeSH
• fluorescenční spektrometrie MeSH
• fosfatidylcholiny MeSH
• fosfoproteiny chemie   metabolismus   MeSH
• fosforylace MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• oční proteiny chemie   metabolismus   MeSH
• proteiny 14-3-3 metabolismus   MeSH
• proteiny vázající GTP - regulátory chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• serin metabolismus   MeSH
• terciární struktura proteinů MeSH
• tryptofan MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH