WHAT controls a beating heart? It seems the life-giving mechanism is simpler than we thought.
Each beat is triggered by a surge of calcium ions that causes millions of overlapping filaments in a heart cell to pull against each other and contract. These filaments are made of two proteins called actin and myosin.
Actin must be 鈥渁ctivated鈥� before contraction can occur and it was thought that both calcium and myosin were necessary for this step. But when Yin-Biao Sun at King鈥檚 College London and , funded by the British Heart Foundation, attached fluorescent probes to rat versions of the proteins, calcium ions alone seemed to activate actin (The Journal of Physiology, ).
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A persistent abnormal heart beat causes many heart problems, so a better understanding of how healthy beating is controlled may aid new drug development.
