Isolation and characterization of membrane-bound ribosomes from nerve cell bodies of immature rat brain-cortex

Lindholm, Dan; Khawaja, Jahangir A.

doi:10.1016/0006-291x(79)90955-0

Cited by 4 publications

(2 citation statements)

References 24 publications

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“…Our present results clearly show that the slower turnover rate of total brain rRNA reflects mainly the markedly slower turnover of cytoplasmic rRNA in neurons. Several studies have shown that neuronal cells are characterized by a distinct prevalence of free over membrane-bound polyribosomes (e.g., Mugnaini and Walberg, 1964; Lindholm and Khawaja, 1979). It would be interesting to see whether the lower turnover rate of cytoplasmic ribosomes in neuronal as compared with oligodendroglial cells is related to the higher proportion of free polyribosomes in these cells.…”

Section: Discussionmentioning

confidence: 99%

Ribosome Biogenesis and Nucleolar Ultrastructure in Neuronal and Oligodendroglial Rat Brain Cells

Stoykova

Dabeva

Dimova

et al. 1985

Journal of Neurochemistry

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The absolute amounts of precursor to ribosomal RNA (pre-rRNA) and ribosomal RNA (rRNA) in isolated rat brain neuronal and oligodendroglial nuclei were determined. The amount of the major pre-rRNA and rRNA species in neuronal nuclei was about twofold higher than in oligodendroglial nuclei. The relative rate of pre-rRNA synthesis in vivo was 2.3- to 2.7-fold higher in neuronal as compared with oligodendroglial nuclei. This corresponds to a 2.7-fold higher activity of the "template-bound" RNA polymerase I in isolated neuronal nuclei, whereas the activity of the "free" enzyme in both neuronal and glial nuclei was almost identical. The higher transcription rates of rRNA genes correlated with the markedly more prominent fibrillar component in neuronal nucleoli. The turnover times of the major pre-rRNA and rRNA species in neuronal and oligodendroglial nuclei were similar, except for 45S pre-rRNA, which turned over at an approximately 1.5-fold slower rate in neuronal nuclei. The relative rates of processing of pre-rRNA and of nucleocytoplasmic transport of rRNA in neuronal cells were approximately 2.7-fold higher than in oligodendroglial cells and corresponded to the differences in rRNA gene transcription rates. The established ribosome formation features correlated with an abundant (neurons) or exceedingly scarce (oligodendrocytes) nucleolar granular component. The turnover rate of cytoplasmic ribosomes in rat brain neurons was twofold slower than in oligodendrocytes, largely because of the about fivefold higher amount of ribosomes in the cytoplasm of neurons. We conclude that ribosome formation and turnover in neuronal and oligodendroglial cells are adapted to the protein synthetic levels in these two types of brain cells.

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Section: Discussionmentioning

confidence: 99%

Ribosome Biogenesis and Nucleolar Ultrastructure in Neuronal and Oligodendroglial Rat Brain Cells

Stoykova

Dabeva

Dimova

et al. 1985

Journal of Neurochemistry

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“…The incubation was carried out for 30 min at 37"C, and the labelled RER was isolated as described earlier (Lindholm and Khawaja, 19790). For brain cortex and liver, RER was prepared from postmitochondrial supernatant fractions previously incubated in an amino acid incorporation system in the presence of 'H-labelled amino acids (Lindholm and Khawaja, 19796).…”

Section: Methodsmentioning

confidence: 99%

Vectorial Discharge and Localization of Nascent Polypeptides in Rough Endoplasmic Reticulum of Developing Neuronal Perikarya of Rat Brain Cortex

Khawaja

Lindholm

1984

Journal of Neurochemistry

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Rough endoplasmic reticulum (RER) prepared from bulk-isolated neuronal perikarya of rat brain cortex of different postnatal ages was found to be active in vectorial discharge of nascent proteins through the membrane; this activity increased with the increasing age of animals and reached maximal values in adults. RER isolated from whole cortical tissue (containing all cell types) exhibited vectorial release only up to 18 days of age; the preparation from adult animals was essentially devoid of secretory activity. Controlled proteolysis of various preparations suggested that in neuronal RER of 8-day-old rats the proportion of nascent proteins operationally retained in the intravesicular space was about twice that retained by cortical preparations. For the purpose of comparison, these parameters were studied also in liver RER.

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Age-dependent inhibition of neuronal protein synthesis by hypothyroidism in the developing rat brain cortex

Lindholm

1982

Biochemical and Biophysical Research Communications

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Isolation and characterization of membrane-bound ribosomes from nerve cell bodies of immature rat brain-cortex

Cited by 4 publications

References 24 publications

Ribosome Biogenesis and Nucleolar Ultrastructure in Neuronal and Oligodendroglial Rat Brain Cells

Ribosome Biogenesis and Nucleolar Ultrastructure in Neuronal and Oligodendroglial Rat Brain Cells

Vectorial Discharge and Localization of Nascent Polypeptides in Rough Endoplasmic Reticulum of Developing Neuronal Perikarya of Rat Brain Cortex

Age-dependent inhibition of neuronal protein synthesis by hypothyroidism in the developing rat brain cortex

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