THE SUBCELLULAR DISTRIBUTION OF CEREBRAL PHOSPHOPROTEINS

Biochem J. 1965 Jun;95(3):883-8. doi: 10.1042/bj0950883.

Abstract

1. The subcellular distribution of the phosphoprotein fraction of grey matter from guinea-pig brain has been determined. Phosphoproteins occurred in all fractions of the tissue, the mitochondrial fraction containing 29%, supernatant 26%, microsomal fraction 23% and nuclear fraction 15%. The quantity of phosphoproteins per unit quantity of protein was highest in the microsomal fraction and lowest (by a factor of nearly 50%) in the mitochondrial fraction. 2. Observations are reported on the nature of the nuclear subfraction believed from earlier work to contain a phosphoprotein sensitive to the effects of electrical pulses applied to cerebral slices in vitro. With respect to its content of phosphoprotein, cholesterol, ribonucleic acid and succinate-dehydrogenase activity, the subfraction resembles the nerve-ending fraction of the mitochondrial fraction, from which it appears to be derived by cross-contamination. Electron microscopy tended to confirm this impression. Reasons are adduced for discounting the earlier claim that the sensitive phosphoprotein is contained in a new subcellular structure distinct from nuclei, mitochondria or microsomes.

MeSH terms

  • Animals
  • Brain Chemistry*
  • Brain*
  • Cell Nucleus*
  • Chemistry Techniques, Analytical*
  • Cholesterol*
  • Guinea Pigs
  • Microscopy, Electron*
  • Microsomes*
  • Mitochondria*
  • Nerve Tissue Proteins*
  • Phosphoproteins*
  • Proteins*
  • RNA*
  • Research*
  • Succinate Dehydrogenase*

Substances

  • Nerve Tissue Proteins
  • Phosphoproteins
  • Proteins
  • RNA
  • Cholesterol
  • Succinate Dehydrogenase