Compartmentation in the cardiac muscle cells <P>

The interaction between enzymes - molecular machines regulating
reactions in the cell - has been known for a while. Recently, in the
heart muscle cells, an unexpected interaction between organelles -
mitochondria, sarcoplasmic reticulum and actomyosin - has been shown.
Using the indirect experimental evidence and mathematical analysis we
have shown that some molecules are trapped in regions of the cell.
Namely, ATP and ADP are trapped between ATP producing and consuming
parts. Intriguingly, there are no clear structural elements which can
limit ATP and ADP movement in the extent predicted by models. Here, I
would give an overview of the experimental data supporting
compartmentation of ADP and ATP leading to the interaction between the
organelles and outline the mathematical approaches used to study such
interaction.