Calcium Uptake and Exchange in Barley Aleurone Layers and Protoplasts During Ca-Stimulated Amylase Secretion

  • Douglas S. Bush
  • Russell L. Jones
Part of the NATO ASI Series book series (volume 104)

Abstract

Extracellular Ca2+ regulates α-amylase secretion in isolated barley aleurone layers. At high Ca2+ concentrations (1–10 mM) the secretion of isozymes of α-amylase with high isoelectric points (high pI) is greatly stimulated. This effect is rapidly reversed by withdrawing Ca2+ and is specific for Ca2+. Extracellular Ca2+ may exert its effect either directly on the plasma membrane or by altering the Ca concentration of some compartment inside the cell. We have determined the influence of extracellular Ca2+ on intracellular Ca pools by measuring Ca uptake and exchange in aleurone layers and by direct measurement of cytoplasmic Ca2+ activity in aleurone protoplasts.

Keywords

Amylase 

Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • Douglas S. Bush
    • 1
  • Russell L. Jones
    • 1
  1. 1.Department of BotanyUniversity of CaliforniaBerkeleyUSA

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