Phosphorylation of Protein Kinase C substrate proteins in rat hippocampal slices - effect of calpain inhibition

• Authors: K. Domanska-Janik , B. Zablocka , T. Zalewska , H. Zajac

Abstracts

EN

Incubation of the acutely dissected rat hippocampal slices in calcium-containing media resulted in spontaneous activation-translocation of classical PKC isoforms and their subsequent (especially g- type) proteolytic degradation. These changes were blocked by calpain inhibitor MDL 28 170 in 100 mM concentration. Rat hippocampal slices were metabolically prelabelled with 32Pi and stimulated with NMDA/glycine, depolarization or phorbol dibutyrate (PDBu) treatment. The basal phosphorylation of specific PKC substrates (MARCKS, neuromodulin and neurogranin) was significantly reduced in non-stimulated slices by MDL pretreatment. In contrast, only the slices where calpain activity was inhibited responded to further NMDA or phorbol dibutyrate stimulation by a substantial increase of PKC-dependent protein phosphorylation. It is concluded that the PKC phosphorylation system is severely affected by non-specific activation and a subsequent, calpain-dependent proteolysis in the acutely prepared hippocampal slices. Calpain inhibition by 100 mM MDL partially prevented these changes and increased stimulus-dependent phosphorylation of PKC-specific protein substrates.

Keywords

EN

CALPAIN; HIPPOCAMPAL SLICE; PROTEIN PHOSPHORYLATION

Discipline

• EXPERIMENTAL_BIOLOGY_&_MEDICINE: EXPERIMENTAL BIOLOGY & MEDICINE

• Publisher: Marceli Nencki Institute of Experimental Biology, Polish Academy of Sciences
• Journal: Acta Neurobiologiae Experimentalis
• Year: 1998
• Volume: 58
• Issue: 4
• Pages: 247-252

Contributors

author

K. Domanska-Janik

author

B. Zablocka

author

T. Zalewska

author

H. Zajac

• Publication order reference: K. Domanska-Janik, Laboratory of Molecular Neuropathology, Department of Neurochemistry, Medical Research Centre, 5 Pawinski St., 02-106 Warsaw, Poland, Email: [e-mail]