Effects of low salt concentration on structural organization and template activity of chromatin in chicken erythrocyte nuclei*

Brasch, Klaus; Seligy, Verner L.; Setterfield, G.

doi:10.1016/s0014-4827(71)80050-2

Cited by 106 publications

(31 citation statements)

References 22 publications

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“…Possible changes in chromatin structure should, of course, be considered in relation to the differences between the inhibitory effects of lysine-rich histone and arginine-rich histone on DNase when it acts on nuclei. The significance of chromatin condensation for the activity of another enzyme, RNA polymerase, has been discussed by other investigators (15,16). Just how significant chromatin condensation in the nucleus is with respect to the data in Table 1 seems to be somewhat doubtful for in experiments on extracted chromatins ( Table 2) there is the same difference between the effects of lysinerich histone and arginine-rich histone in blocking the action of DNase.…”

Section: Resultsmentioning

confidence: 92%

Blocking by Histones of Accessibility to DNA in Chromatin: Addition of Histones

Mirsky¹,

Silverman²,

Panda³

1972

Proc. Natl. Acad. Sci. U.S.A.

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The blocking effect of histones on accessibility of DNA to DNase has been studied by addition of various histones to chromatin in intact or histone-depleted thymus nuclei (those from which all lysine-rich histone was removed and those from which much of the arginine-rich histone was removed) and to deoxyribonucleoprotein (chromatin) extracted from nuclei. In each case lysine-rich histone, weight for weight, blocks accessibility more effectively than does arginine-rich histone. Fractions of the arginine-rich histone differ considerably from each other in their blocking efficacy. Phosphorylation of lysine-rich histone tempers its blocking effectiveness.

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Section: Resultsmentioning

confidence: 92%

Blocking by Histones of Accessibility to DNA in Chromatin: Addition of Histones

Mirsky¹,

Silverman²,

Panda³

1972

Proc. Natl. Acad. Sci. U.S.A.

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“…In general, all the properties studied for gander erythrocyte chromatin compare favorably with those obtained for chicken erythrocyte chromatin [2, 12,13,17,24]. However, while the CD spectra for gander and chicken erythrocyte 121 chromatin are similar, they both appear to differ from the properties of chromatin from other systems [1,[3][4][5][6][7] 1,3,7].…”

Section: Discussionmentioning

confidence: 89%

“…Template activities of chromatin and DNA were determined as previously described [12,13]. DNAdependent RNA polymerse was prepared from spraydried Micrococcus Zuteus cells (Miles Chemical Co.) according to Nakamoto et al [21].…”

Section: Template Activitymentioning

confidence: 99%

“…I n all experiments fraction VI (after DEAE-cellulose chromatography) polymerase was used. A complete template activity assay contained: [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] cyte chromatin [12,13,24]. Moreover, under similar conditions and extraction methods, the selective removal of certain histones was achieved.…”

Section: Template Activitymentioning

confidence: 99%

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Circular Dichroism of Avian‐Erythrocyte Chromatin and Ethidium Bromide Bound to Chromatin

Williams

Lurquin

Seligy

1972

European Journal of Biochemistry

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The circular dichroism of mature gander erythrocyte chromatin was compared with that of partially dehistonized chromatin and deproteinized DNA. The ellipticity at 275 nm for native chromatin was found to be three-times less than that for DNA. The 275-nm transition was gradually increased in magnitude upon removal of histones. Selective removal of the very lysinerich histone I and the erythrocyte-specific histone V, but not histone I alone, resulted in a significant increase in transcription in vitro and ethidium bromide primary binding properties of chromatin. Concomitant with these changes a "blue shift" of the positive DNA band from 282 nm for native chromatin to 275 nm for purified DNA was observed.Optimal conditions for circular dichroism studies in ethidium bromide bound to DNA and native chromatin were determined.The circular dichroic spectra of ethidium bromide bound to native chromatin and partially deproteinized chromatin were found to be essentially the same as that exhibited by ethidiumbromide . DNA complexes. However, the ellipticity of the dye bound to native chromatin was smaller than that when ethidium bromide was bound to DNA. The 310-nm dye transition was increased after the removal of chromosomal proteins. Selective removal of histone I and V was found to generate the most notable increment in ellipticity.The represent results are consistent with recent interpretations on how ethidium bromide interacts with chromatin ; native chromatin has fewer ethidium bromide primary binding sites than deproteinized DNA ; the mode of this dye interaction in these two systems is nearly the same, if not identical.Several circular dichroic spectral studies on chromatin isolated from various tissues have been made [l-71. The results generally indicate that the conformation of DNA in chromatin is significantly different from that of deprotcnizcd DNA.The use of the intercalative dye ethidium bromide [8,9] as a probe for studying the state of DNA in the isolated chromatin or nucleoprotein complexes of interphase chromosomes has recently been considered for calf thymus [lo] and avian erythrocytes [ll]. Both studies have demonstrated a decrease in ethidium bromide primary or strong binding to chromatin in comparison to deproteinized DNA. However, it appears that chromatin from biologically inactive erythrocytes binds much less ethidium bromide than chromatin from calf thymus, and that the erythrocyte-specific histone V, or f2c [il-141 is fundamental in the process which Abbreviations. CD, circular dichroism ; DNA-P, DNAEnzyme. Micrococcus luteus DNA-dependent RNA polyphosphate. merase (EC 2.7.7.6).limits the extent of ethidium bromide primary binding.Although fluorescence data suggest that ethidium bromide binding sites in chromatin and in DNA are very much alike [lo], additional evidence is required to further establish the nature of the DNA available for ethidium bromide binding in chromatin. Dalgleish et al. [15] have shown that ethidium bromide acquires optical activity upon binding to DNA, the magnitude of the 3...

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“…3a, b) was obtained with RNA isolated from total cells and isolated nuclei [67] from red blood cell populations that were enriched in erythroblasts by phenyl-hydrazine treatment. The pattern shows a clo se resemblance to those of nuclear RN As from avian erythroblasts (cf [38 , 53]) and is different from the very low molecular weight RNA which some authors have reported in chicken erythrocyte and erythroblast chromatin [2,12].…”

Section: Rna Synthesis In Hen Erythrocytes 89mentioning

confidence: 90%

Characterization and localization of the RNA synthesized in mature avian erythrocytes

Zentgraf

Scheer

Franke

1975

Experimental Cell Research

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Experimental Cell Research 96 (1975) RNA present and synthesized in mature hen erythrocytes in vivo and in vitro has been studied with electron microscopic , autoradiographic , and biochemical methods. The average hen erythrocyte contains a minimum of 0.02-0.04 pg RN A which is predominantly, if not exclusively, located in the nucleus. The incorporation of[3HJuridine into this RNA is very low but is clearly demonstrable in vivo and in vitro using different incubation media. The specific efficiencies of the incorporation assays are compared. The incorporated radioactivity is contained in RN A as shown by its selective sensitivity to hydrolysis in mild alkali and with ribonuclease a nd is not hybridized to DNA as shown by Cs.SO" gradient centrifugation of total hen erythrocyte nucleic acids. LiCI precipitation as well as gel electrophoresis on agarose under denaturing and non-denaturing conditions has revealed that this labelled RNA is of high-molecular weight a nd covers a broad range from ca 0.25 to 5.0 million D, with gel-electrophoretically detectable peaks at positions corresponding to 1.8, 1.0 and 0.5 million D. The pattern obtained is virtually identical after the different incorporation condi tion s and was also sim il ar to that obtained in reticulocyte cells of animals made anaemic with phenylhydrazine. The incorporation is inhibited by actinomycin D with a sensitivity characteristic for mRN A formation a nd is also reduced in the presence of a-amanitin. The labelled RNA remains within th e confinements of the nucleus and does not seem to be transported into the cytoplasm. It appears to be preferentially enriched in the interchromatinic channels . It is concluded that mature hen erythrocytes are capable of transcribing a small part of their genome into pre-mRNA at a very reduced level but that this RNA is not only excluded from functioning in tra nslation but also from nucleocytoplasmic transport. The findings are discussed in relation to the controversial literatu re in this field, a nd possible functions of thi s RNA are hypothesized.Various forms of cell differentiation are characterized by a progressive cessation of the sy nthesis of most, if not all, classes of RNA. In some late stages of such differentiation processes one even notes a general breakdown of RNA-containing structures and the mature cell is almost emptied of RNA . The formation of the red blood cell, in particular in animals with nucleated erythrocytes , has become of special importance in studie s of the programmed switch-off sequence of the transcription of most, and finally perhaps of all, genes. It has been shown that during erythropoiesis the nuclear content and the nuclear envelope is greatly reduced , the chromatin condenses and contains an additional special histone , the nucleolus disappears, concomitant with the cessation of ribosome formation , the number of transcribed genes decreases , leaving the transcription of one class of genes in the Exprl Cell Res 96 (1975)

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Effects of low salt concentration on structural organization and template activity of chromatin in chicken erythrocyte nuclei*

Cited by 106 publications

References 22 publications

Blocking by Histones of Accessibility to DNA in Chromatin: Addition of Histones

Blocking by Histones of Accessibility to DNA in Chromatin: Addition of Histones

Circular Dichroism of Avian‐Erythrocyte Chromatin and Ethidium Bromide Bound to Chromatin

Characterization and localization of the RNA synthesized in mature avian erythrocytes

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