Inorganic Cations in the Cell Nucleus

Tres, Laura L.; Kierszenbaum, Abraham L.; Tandler, C. J.

doi:10.1083/jcb.53.2.483

Cited by 22 publications

(2 citation statements)

References 31 publications

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“…In rat liver cells, for example, the nuclear Ca/Mg concentration can be approximated to be -25 mM (for review see reference 25). Interestingly, Ca and Mg can be either uniformly distributed or sequestered at particular sites, depending on the RNA synthetic activity as revealed, for example, in Sertoli cell nuclei (30). Thus, it would be attractive to speculate that, in vivo, the matrix equivalent is also capable of only local swelling and contraction.…”

Section: Discussionmentioning

confidence: 99%

Reversibly contractile nuclear matrix. Its isolation, structure, and composition.

Wunderlich¹,

Herlan²

1977

The Journal of Cell Biology

126

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From Tetrahymena macronuclei we have isolated a reversibly contractile nucleoskeleton, i.e., an "expanded" nuclear matrix which reversibly contracts when the total concentration of the bivalent cations, Ca and Mg (3:2), is decreased to 5 mM or increased to 125 raM. During contraction the average diameter of the expanded matrix becomes reduced by about 24%; this corresponds to a volume contraction of about 55%. The reversible contraction of the nuclear matrix does not depend on ATP and cannot be inhibited by salyrgan. The expanded matrix is obtained by removing carefully from the macronuclei 89.7% of the phospholipid, 99,6% of the DNA, 98.5% of the RNA, and 74.8% of the protein by treatment with Triton X-100 and digestion with DNase and RNase followed by an extraction with 2 M NaCl. Electron microscopy reveals, within the expanded matrix, residual equivalents to the structures characteristic for macronuclei: (a) a residual nuclear envelope with nuclear pore complexes; (b) residual nucleoli at the periphery; (c) a fibrillar internal network. The expanded matrix is essentially composed of proteins (96.2%) and traces of DNA (0.8%), RNA (0.5%), phospholipid (1.6%), and carbohydrates (0.9%). The last, which have been determined by gas chromatography, contain glucose, mannose, and an unidentified sugar in the ratio 1:5.4:5.7. The ratio of acidic to basic amino acids of the expanded matrix is 1.55. Sodium dodecyl sulfate (SDS) gel electrophoresis reveals a predominant protein with a mol wt of 18,000 which is apparently involved in the reversible contractile process. The mechanism of this reversible contraction of the expanded matrix remains to be elucidated, but it differs both from actin-myosin contraction systems and from the contractile spasmoneme system in vorticellids.Considerable evidence shows that cell nuclei vary in their size as for example during the cell cycle and cell differentiation, or with circadian periodicity (14). In particular, nuclear enlargement precedes as a prerequisite the onset of DNA synthesis in vivo (12,15) and in vitro (3), while nuclear contraction appears to accompany cessation of DNA synthesis (13). LeStourgeon et aI. (20) have previously suggested that nuclear contractile proteins of the actin-myosin type regulate nuclear contraction and swelling (cf. also reference 9).Recent findings, however, suggest that not actin-myosin type proteins, but rather other acidic proteins determine the internal organization and overall form of cell nuclei. Thus, Berezney and Coffey (4) have isolated, from rat liver nuclei, a T

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Section: Discussionmentioning

confidence: 99%

Reversibly contractile nuclear matrix. Its isolation, structure, and composition.

Wunderlich¹,

Herlan²

1977

The Journal of Cell Biology

126

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“…Cobalt is known to act on RNA transcription. Tres et al (1972) observed a positive correlation between RNA synthetic activity and the quantity of cations in the nucleus in mouse cells, results that indicated the effect of cobalt chloride on RNA polymerase, the activity of which is dependent on divalent cations. Okail (2010) showed that cobalt chloride is a chemical inducer of hypoxiainducible factor-1α protein and increases the proliferation of a U251 human glioblastoma cell χ 2 = 0.5633; P > 0.05.…”

Section: Resultsmentioning

confidence: 81%

Cobalt chloride induces metaphase when topically applied to larvae and pupae of the stingless bee Melipona scutellaris (Hymenoptera, Apidae, Meliponini)

Ueira-Vieira

Tavares²,

Morelli³

et al. 2013

Genet. Mol. Res.

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ABSTRACT. In order to optimize preparations of bee metaphases, we tested cobalt chloride, which has been used as a metaphase inducer in other organisms, such as hamsters and fish. Four microliters of 65 mM cobalt chloride aqueous solution was topically applied to larval and pupal stages of the stingless bee Melipona scutellaris. The cerebral ganglion was removed after treatment and prepared for cytogenetic analysis. Identically manipulated untreated individuals were used as controls. The number of metaphases was increased 3-fold in treated individuals compared to controls. The micronucleus test showed no mutagenic effects of cobalt chloride on M. scutellaris cells. We concluded that cobalt chloride is a metaphase-inducing agent in M. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 12 (2): 2032-2037 (2013 Cobalt chloride induces metaphase in stingless bees 2033 scutellaris, thus being useful for cytogenetic analyses.

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Cytochemical localization of cations in the testis of the syrian hamster, utilizing potassium‐pyroantimonate

Gravis

1979

Am. J. Anat.

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Pyroantimonate has long been used as a cytochemical technique for the localization of cations. Although the technique was originally alleged to be specific for Na+, other cations, including Mg++, Ba++, Ca++, Zn++ and polycationic amines, form pyroantimonate precipitates. In seminiferous tubules treated with antimonate-osmium fixation, the nuclei of the Sertoli cells and germ cells contained precipitates. In regions of condensed chromatin the precipitates were dense while, in dispersed chromatin, precipitates were sparse or absent. It is postulated that the dense precipitates observed in the condensed chromatin may represent an accumulation of calcium that may facilitate chromatin condensation. The Sertoli cell nucleolar apparatus contained light precipitates in the pars amorpha, moderate precipitates in the nucleolonema, and heavy precipitates in the perinucleolar heterochromatin bodies. The nuclei of the maturation-phase spermatids lacked any Precipitates. The perinuclear ring of the acrosome-phase spermatids contained pyroantimonate deposits. In the maturation-phase spermatids, staining occurred in the postacrosomal dense lamina, in the subacrosomal space between the perforatorium and the inner acrosomal membrane, and in the central mass of the residual bodies. Since the postacrosomal dense lamina is the portion of the spermatozoon that initially fuses with the ovum, it is postulated that its cationic properties in some way facilitate this fusion.Pyroantimonate is a unique anion which can be dissolved as the potassium salt but forms insoluble precipitates with other cations. The low molecular weight of pyroantimonate and its electron-opacity render it useful for ultrastructural localization of cations. Komnick ('62) was the first to use potassium pyroantimonate as a cytochemical technique for localization of cations. Although the method was originally alleged to be specific for the localization of sodium, it was later shown that other cations form pyroantimonate salts. Several lines of evidence indicate that pyroantimonate forms insoluble precipitates with B a + + , Ca++, Mg++, Na+, Zn++, glycogen, histamine, spermine, and histones; potassium-antimonate may form in sites of lowered pH or when the pH of the cytochemical medium is not properly controlled (Bulger, '69; Legato and Langer, '69; Lane and Martin, '69; Tisher et al., '69; Torack and LaValle, '70; Clark and Ackerman, '71; Klein et al., '72; Spicer and Swanson, '72).

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Inorganic Cations in the Cell Nucleus

Cited by 22 publications

References 31 publications

Reversibly contractile nuclear matrix. Its isolation, structure, and composition.

Reversibly contractile nuclear matrix. Its isolation, structure, and composition.

Cobalt chloride induces metaphase when topically applied to larvae and pupae of the stingless bee Melipona scutellaris (Hymenoptera, Apidae, Meliponini)

Cytochemical localization of cations in the testis of the syrian hamster, utilizing potassium‐pyroantimonate

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