Calcium-dependent proteases: an enzyme system active at cellular membranes?

FASEB J. 1987 Aug;1(2):110-5. doi: 10.1096/fasebj.1.2.2886390.

Abstract

Proteases having a neutral pH optimum and an absolute requirement for calcium ion are found in virtually all mammalian cells. Association of calcium-dependent proteases and a specific inhibitor protein with biological membranes seems to be an important regulatory feature of this proteolytic system, and it is likely that membranes are preferred sites for calcium-dependent protease action. Several recent hypotheses for the physiological function of calcium-dependent proteolysis are consistent with a membrane-associated protease action. Calcium-dependent proteases may participate in cell membrane fusion: the proteolysis of membrane proteins, which is required for the efficient fusion of erythrocytes, may be catalyzed by these enzymes. There is also evidence for the involvement of calcium-dependent proteolysis in postsynaptic membrane remodeling in the hippocampus after long-term potentiation. Although the relationship of the proteolysis to synaptic function is not known, it could have important physiological or pathophysiological consequences. Finally, it has recently been suggested that calcium-dependent proteolysis may be a physiologically significant mechanism for activating membrane-associated protein kinase C after exposure of some cell types to phorbol esters or other mitogens. Further pursuit of these hypotheses may reveal a novel role for intracellular calcium-regulated proteolysis in membrane-associated cell functions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Calcium / metabolism
  • Calpain / physiology*
  • Cell Fusion
  • Enzyme Activation
  • Glutamates / toxicity
  • Glutamic Acid
  • Isoenzymes / physiology
  • Membrane Proteins / physiology*
  • Memory / physiology
  • Protein Kinase C / metabolism

Substances

  • Glutamates
  • Isoenzymes
  • Membrane Proteins
  • Glutamic Acid
  • Protein Kinase C
  • Calpain
  • Calcium