Related Experiment Video
Updated: Mar 16, 2026

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein
Published on: June 30, 2019
The structural basis for calcium inhibition of lipid kinase PI4K IIalpha and comparison with the apo state
A Baumlova1, J Gregor, E Boura
1Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic. boura@uochb.cas.cz.
Abstract:
PI4K IIalpha is a critical enzyme for the maintenance of Golgi and is also known to function in the synaptic vesicles. The product of its catalytical function, phosphatidylinositol 4-phosphate (PI4P), is an important lipid molecule because it is a hallmark of the Golgi and TGN, is directly recognized by many proteins and also serves as a precursor molecule for synthesis of higher phosphoinositides. Here, we report crystal structures of PI4K IIalpha enzyme in the apo-state and inhibited by calcium. The apo-structure reveals a surprising rigidity of the active site residues important for catalytic activity. The structure of calcium inhibited kinase reveals how calcium locks ATP in the active site.
More Related Videos
Related Concept Videos
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
IP3/DAG Signaling Pathway
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
The JAK-STAT Signaling Pathway
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains...

