The presence of a secretory phospholipase A2 in the nuclei of neuronal and glial cells of rat brain cortex.
Confocal immunofluorescence analysis indicated a relatively high localization of group V secretory phospholipase A(2) (GV) in the nuclei of cultured PC12 and U251 astrocytoma cells. Here, we report the biochemical evidence for the presence of a secretory PLA(2) in the nuclei of neuronal and glial cells from rat brain cortex. Enzymic activity was determined using [(3)H]oleate labelled Escherichia coli membranes in intact nuclei and in their soluble fractions in which the specific activity was significantly more elevated. The treatment of soluble nuclear fractions with inhibitors of cytosolic Ca(2+)-dependent or Ca(2+)-independent phospholipases A(2) was ineffective whereas DTT or Indoxam, a specific inhibitor of all isoforms of sPLA(2), abolished enzyme activity. The enzyme was identified as group V secretory phospholipase A(2) (GV) by Western blot analysis and its nucleoplasmic localization was demonstrated by CLSM.
Nardicchi
Vincenza
V
Department of Internal Medicine, Biochemistry Section, University of Perugia, Via del Giochetto, I-06122 Perugia, Italy.
Macchioni
Lara
L
Ferrini
Monica
M
Goracci
Gianfrancesco
G
D000818:Animals; D002219:Carbamates / Q000494:pharmacology; D002467:Cell Nucleus / Q000201:enzymology; D002540:Cerebral Cortex / Q000166:cytology / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D054505:Group V Phospholipases A2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007212:Indolizines / Q000494:pharmacology; D018613:Microscopy, Confocal; D009457:Neuroglia / Q000201:enzymology; D009474:Neurons / Q000201:enzymology; D051381:Rats
D002219:Carbamates; D004791:Enzyme Inhibitors; D007212:Indolizines; C119389:indoxam; D054505:Group V Phospholipases A2