Lysosomal origin of chicken erythrocyte nuclear protease

Lindsey, George G.; Thompson, Patrick; Holt, Claus von

doi:10.1016/0014-5793(81)80948-9

Cited by 9 publications

(8 citation statements)

References 21 publications

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“…This “neutral protease” activity was later attributed to different enzyme activities in different tissues and animals . At least three different proteases were pursued in search of the “neutral protease”, one of which cleaves a histone H3K 23 and one that was attributed to cytoplasmic contamination . One report mentions a high molecular weight (HMW) “protease A” that could be converted into a low and an intermediate MW protease by high pH or NaCl concentrations .…”

Section: Histone Proteolysismentioning

confidence: 99%

Histone proteolysis: A proposal for categorization into ‘clipping’ and ‘degradation’

et al. 2014

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We propose for the first time to divide histone proteolysis into “histone degradation” and the epigenetically connoted “histone clipping”. Our initial observation is that these two different classes are very hard to distinguish both experimentally and biologically, because they can both be mediated by the same enzymes. Since the first report decades ago, proteolysis has been found in a broad spectrum of eukaryotic organisms. However, the authors often not clearly distinguish or determine whether degradation or clipping was studied. Given the importance of histone modifications in epigenetic regulation we further elaborate on the different ways in which histone proteolysis could play a role in epigenetics. Finally, unanticipated histone proteolysis has probably left a mark on many studies of histones in the past. In conclusion, we emphasize the significance of reviving the study of histone proteolysis both from a biological and an experimental perspective.

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Section: Histone Proteolysismentioning

confidence: 99%

Histone proteolysis: A proposal for categorization into ‘clipping’ and ‘degradation’

et al. 2014

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“…Further investigations showed that the degradation in the pH range 5-7 (predominantly degradation of H2A and H3) was similar to that obtained by adding calf thymus lysosome extracts to whole histone and it was therefore concluded that at least some of this degradation could be lyso- somal in origin, deriving from traces of lysosomes in the nuclei preparations (22). The contamination of nuclei preparations with lysosomes or lysosomal enzymes has been previously reported (15,23). Proteolysis in the pH range 5-7 was therefore not studied further.…”

Section: Resultsmentioning

confidence: 99%

“…Unfortunately these individual observations are difficult to correlate and much uncertainty exists in the literature as to the number, nature and specificities of such enzymes. Indeed, the possibility exists that at least some of these enzymes may originate from contaminating organelles (14,15). However, until such time as these nuclear enzymes have been isolated and their in vivo substrates identified one can only speculate as to the functions of such enzymes.…”

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confidence: 99%

Chromatin associated protease from calf thymus

Dyson

Walker

1984

International Journal of Peptide and Protein Research

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We have identified and purified a chromatin bound protease from calf thymus. The purified enzyme cleaves histone H1 when whole histone is used as substrate. The enzyme is inhibited by Soya bean trypsin inhibitor, but not by PMSF, EDTA, pepstatin or Ellman's reagent. Further studies have shown that H1° and histone H5 are also cleaved by this enzyme, and that when HMG 1 and 2 are used as substrate HMGl alone is degraded to give specific degradation products. We have also shown that the enzyme co-isolates with whole histone prepared by acid extraction of calf thymus nuclei, but interestingly it is not present in whole histone samples prepared in the same manner from pig thymus. A second chromatin bound protease which specifically cleaves histone H3 when whole histone is used as substrate has also been identified during the course of this work.

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“…Under these conditions the aspartate protease present in chicken chromatin is inactive [6]. The H3-H4 tetramer containing fractions were pooled and the tetramer precipitated with 0.7 saturation ammonium sulphate.…”

Section: Histone Purificationmentioning

confidence: 99%

“…The natural H3-I-I4 tetramer of chicken erythrocyte chromatin was prepared essentially as described previously except that the exclusion chromatography used to separate Hs-H4 tetramer from H3-I$ dimer and I+A--I-I~B dimer was carried out at 150 mM NaCl, 50 mM phosphate (pH 7.4) instead of 2 M NaCl, 50 mM acetate (pH 5.0) to avoid proteolysis. Under these conditions the aspartate protease present in chicken chromatin is inactive [6]. The H3-H4 tetramer containing fractions were pooled and the tetramer precipitated with 0.7 saturation ammonium sulphate.…”

Section: Histone Purificationmentioning

confidence: 99%

The reconstitution of histone H₃H₄ tetramer from acid extracted histones in the absence of urea

et al. 1982

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Simple mixing of acid purified histones H3 and H4 in equimolar quantities at low ionic strength near pH 7 does not yield the tetramer but rather a high M, aggregate. Dialysis of acid extracted total or core histones into 2 M NaCl 150 mM phosphate (pH 7.4) followed by fractionation of the histone complexes at lower ionic strength (150 mM NaCl) results in an Hs-H4 tetramer of a structure identical to that derived from salt-extracted histones. Dialysis of acid extracted total or core histones directly into the lower ionic strength buffer with subsequent fractionation, results in Hs-H4 tetramer of closely similar structure.Histone Reconstitution H3-H4 tetramer (Chicken erythrocyte chromatin)

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Lysosomal origin of chicken erythrocyte nuclear protease

Cited by 9 publications

References 21 publications

Histone proteolysis: A proposal for categorization into ‘clipping’ and ‘degradation’

Histone proteolysis: A proposal for categorization into ‘clipping’ and ‘degradation’

Chromatin associated protease from calf thymus

The reconstitution of histone H₃H₄ tetramer from acid extracted histones in the absence of urea

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Lysosomal origin of chicken erythrocyte nuclear protease

Cited by 9 publications

References 21 publications

Histone proteolysis: A proposal for categorization into ‘clipping’ and ‘degradation’

Histone proteolysis: A proposal for categorization into ‘clipping’ and ‘degradation’

Chromatin associated protease from calf thymus

The reconstitution of histone H3H4 tetramer from acid extracted histones in the absence of urea

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The reconstitution of histone H₃H₄ tetramer from acid extracted histones in the absence of urea