Nuclear translocation of cytosolic phospholipase A2 is induced by ATP depletion

J Biol Chem. 2001 Aug 10;276(32):29899-905. doi: 10.1074/jbc.M103758200. Epub 2001 Jun 6.

Abstract

Phospholipase A(2) (PLA(2)) enzymes may play a role in cellular injury due to ATP depletion. Renal Madin-Darby canine kidney cells were subjected to ATP depletion to assess the effects of cellular energy metabolism on cytosolic PLA(2) (cPLA(2)) regulation. ATP depletion results in a decrease in soluble cPLA(2) activity and an increase in membrane-associated activity, which is reversed upon restoration of ATP levels by addition of dextrose. In ATP-depleted cells cPLA(2) mass shifts from cytosol to nuclear fractions. GFP-cPLA(2) is localized at the nuclear membrane of stably transfected ATP-depleted LLC-PK(1) cells under conditions where [Ca(2+)](i) is known to increase. cPLA(2) translocation does not occur if the increase in [Ca(2+)](i) increase is inhibited. If [Ca(2+)](i) is allowed to increase when ATP is depleted and the cells are then lysed, cPLA(2) remains associated with nuclear fractions even if the homogenate [Ca(2+)] is markedly reduced. In contrast, cPLA(2), which becomes associated with the nucleus when [Ca(2+)](i) is increased using ionophore, readily dissociates from the nuclear fractions of ATP-replete cells upon reduction of homogenate [Ca(2+)]. Okadaic acid inhibits the ATP depletion-induced association of cPLA(2) with nuclear fractions. Thus energy deprivation results in [Ca(2+)]-induced nuclear translocation, which is partially prevented by a phosphatase inhibitor.

Publication types

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

MeSH terms

  • Active Transport, Cell Nucleus*
  • Adenosine Triphosphate / metabolism*
  • Animals
  • Blotting, Western
  • Calcimycin / pharmacology
  • Calcium / metabolism
  • Cell Line
  • Cell Nucleus / enzymology*
  • Cell Nucleus / metabolism
  • Cyanides / pharmacology
  • Cytosol / enzymology*
  • Deoxyglucose / pharmacology
  • Dogs
  • Egtazic Acid / analogs & derivatives
  • Egtazic Acid / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Green Fluorescent Proteins
  • Hydrogen-Ion Concentration
  • Kidney / enzymology*
  • Luminescent Proteins / metabolism
  • Microscopy, Fluorescence
  • Okadaic Acid / pharmacology
  • Phospholipases A / metabolism*
  • Phospholipases A2
  • Plasmids / metabolism
  • Time Factors
  • Transfection

Substances

  • Cyanides
  • Enzyme Inhibitors
  • Luminescent Proteins
  • Green Fluorescent Proteins
  • Okadaic Acid
  • Calcimycin
  • Egtazic Acid
  • Adenosine Triphosphate
  • Deoxyglucose
  • Phospholipases A
  • Phospholipases A2
  • 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
  • Calcium