One Scaffold, Two Conformations: The Ring-Flip of the Messenger InsP₈ Occurs under Cytosolic Conditions.

ABSTRACT: Inositol poly- and pyrophosphates (InsPs and PP-InsPs) are central eukaryotic messengers. These very highly phosphorylated molecules can exist in two distinct conformations, a canonical one with five phosphoryl groups in equatorial positions, and a "flipped" conformation with five axial substituents. Using ¹³C-labeled InsPs/PP-InsPs, the behavior of these molecules was investigated by 2D-NMR under solution conditions reminiscent of a cytosolic environment. Remarkably, the most highly phosphorylated messenger 1,5(PP)₂-InsP₄ (also termed InsP₈) readily adopts both conformations at physiological conditions. Environmental factors-such as pH, metal cation composition, and temperature-strongly influence the conformational equilibrium. Thermodynamic dat

SUBMITTER: Kurz L 

PROVIDER: S-EPMC10135964 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature