The role of calcium in aggregation and development of Dictyostelium.
Changes in cytosolic Ca2+ play an important role in a wide array of cell types and the control of its concentration depends upon the interplay of many cellular constituents. Resting cells maintain cytosolic calcium ([Ca2+]i) at a low level in the face of steep gradients of extracellular and sequestered Ca2+. Many different signals can provoke the opening of calcium channels in the plasma membrane or in intracellular compartments and cause rapid influx of Ca2+ into the cytosol and elevation of [Ca2+]i. After such stimulation Ca2+ ATPases located in the plasma membrane and in the membranes of intracellular stores rapidly return [Ca2+]i to its basal level. Such responses to elevation of [Ca2+]i are a part of an important signal transduction mechanism that uses calcium (often via the binding protein calmodulin) to mediate a variety of cellular actions responsive to outside influences.
Department of Biochemistry, University of Oxford, United Kingdom.
P C
PC
Newell
D
D
Malchow
J D
JD
Gross
D000818:Animals; D002118:Calcium / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000502:physiology; D002633:Chemotaxis; D006152:Cyclic GMP / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology; D004023:Dictyostelium / Q000254:growth & development*
D000252:Calcium-Transporting ATPases; D006152:Cyclic GMP; D002118:Calcium