The fine structure of nuclei as revealed by electron microscopy

Yasuzumi, G.; Tsubo, Isako

doi:10.1016/0014-4827(66)90055-3

Cited by 77 publications

(19 citation statements)

References 27 publications

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“…Unfortunately, the method is susceptible to a number of possible artifacts which allow a t most qualified acceptance of this finding until more rigorous controls are employed. However, similar localization in nuclei of mouse choroid plexus epithelial cells also has been described by Yasuzumi and Tsubo [2], using methods and material which they claim are relatively free from artifacts. The existence of nucleoside triphosphatase a t these loci could have important implications and warrants further investigation concerning possible function in nuclear membrane transport.…”

Section: It Was Initially Observed In Early 1964 At Thesupporting

confidence: 77%

Evidence for an Amino Acid Transport System in Nuclei Isolated from Embryonic Heart

Klein

Horton

Thureson‐Klein

1968

European Journal of Biochemistry

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Nuclei isolated from embryonic myocardium of the chick possess an ATP phosphohydrolase and are capable of accumulating amino acid in a diffusible form in large excess of environmental levels. The enzyme is of relatively high specific activity and shows preference for ATP compared to other possible substrates. Properties common to both the enzyme and to net amino acid uptake are requirements for ATP, Mg++, Na+ or K+ and a critical level of Ca++. I n the presence of Na+ or K+, both L-and D-forms of several amino acids will further stimulate ATP hydrolysis. The latter stimulation by a-alanine and the net uptake of this amino acid can both be completely inhibited by similar concentrations of ouabain, EGTA and excess Ca++. Ouabain has no effect on basic Mg++-activated ATP hydrolysis or that stimulated by the addition of Na+ or K+. It is concluded that these nuclei possess an ATP phosphohydrolase-linked transport system for a-alanine and probably for other amino acids:Implications of this transport system are discussed relative to the ultrastructure and compartmentalization of the cardiac cell.It was initially observed in early 1964 at the Wenner-Gren Institute, Stockholm by Klein and Afzelius [I] that "presumptive" ATP hydrolysis activity could be localized close t o the inner nuclear membrane and prominently a t nuclear pores of chick embryonic ventricular muscle, using a modified histochemical test in con junction with electron microscopy. Unfortunately, the method is susceptible to a number of possible artifacts which allow a t most qualified acceptance of this finding until more rigorous controls are employed. However, similar localization in nuclei of mouse choroid plexus epithelial cells also has been described by Yasuzumi and Tsubo [2], using methods and material which they claim are relatively free from artifacts. The existence of nucleoside triphosphatase a t these loci could have important implications and warrants further investigation concerning possible function in nuclear membrane transport. That this topic is of major concern to those interested in the role of the nucleus in nucleoprotein synthesis and nuclearcytoplasmic exchange is evidenced from numerous speculations found in the recent literature [3 -91.Unusual Abbreviations. EGTA, ethylene glycol bis(Paminoethy1ether)-N,N'-tetraacetic acid; TES, N-Tris-(hydroxymethyl)methyl-2-aminoethane sulfonic acid; PPO, 2,5-diphenyloxazole; POPOP, 1,4-bis-(5-phenyloxazolyl-2)-benzene.Enzymes. ATPase or ATP phosphohydrolase (EC 3.6.1.3) ; alkaline phosphatase or orthophosphoric monoester phosphohydrolase (EC 3.1.3.1) ; acid phosphatase or orthophosphoric monoester phosphohydrolase (EC 3.1.3.2).Subsequent studies in this laboratory on embryonic heart nuclei confirmed the presence of a Mg++-activated adenosine triphosphate phosphohydrolase (ATPase) of relatively high specific activity and with preference for ATP compared to other nucleoside triphosphates and a variety of di-and monophosphates. A number of chemical and physical properties of the enzyme have been de...

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Section: It Was Initially Observed In Early 1964 At Thesupporting

confidence: 77%

Evidence for an Amino Acid Transport System in Nuclei Isolated from Embryonic Heart

Klein

Horton

Thureson‐Klein

1968

European Journal of Biochemistry

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“…However, the above results suggest that this marker cannot be used when preparations have been made in high-ionic-strength media, or when there are high concentrations of endogenous RNA or ribonucleoprotein to interact with and stimulate the enzyme. Moreover, if cells or cell fractions have been subjected to conditions sufficiently vigorous to disrupt the nuclear envelope, it should be remembered that the enzyme is probably associated only with the pore complexes (Yasuzumi & Tsubo, 1966;Franke, 1974) and will not therefore indicate the presence of inner or outer nuclearmembrane vesicles. It must also be demonstrated that the products ofstimulated hydrolysis are ADP and Pi, rather than PPi.…”

Section: Discussionmentioning

confidence: 99%

“…Several authors have described a nucleoside triphosphatase (Mg2+-dependent ATPase,t EC 3.6.1.3) in mammalian liver nuclear envelopes [see Franke (1974) for a thorough review], and there is evidence that this activity is localized exclusively in or near the nuclear pore complexes (Yasuzumi & Tsubo, 1966;Franke, 1974). The enzyme has been characterized with respect to its substrate specificity and other properties (Agutter et al, 1976b), its kinetic behaviour (Agutter et al, 1976c) and its sensitivity to various inhibitors (Agutter et al, 1976d).…”

mentioning

confidence: 99%

Ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. A possible enzymic marker for the nuclear envelope

Agutter¹,

Harris²,

Stevenson³

1977

Biochemical Journal

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1. The specific activity of rat and pig liver nuclear-envelope nucleoside triphosphatase (EC 3.6.1.3) decreases when the system is depleted of RNA. The activity can be restored by adding high concentrations of yeast RNA to the assay medium. 2. Exogenous RNA also increases the activity of the enzyme in control envelopes (not RNA-depleted). The effect appears to be largely specific for poly(A) and poly(G); it is not stimulated by rRNA or tRNA preparations, ribonuclease-hydrolysed RNA, AMP, or double-or singlestranded DNA. 3. Inhibitors of the enzyme, in concentrations at which half-maximal inhibition of the enzyme is achieved, do not affect the percentage stimulation of the enzyme by yeast RNA. 4. The stimulation is abolished by the inclusion of l5OnM-KCl or -NaCl in the assay medium, but not by increasing the assay pH to 8.5. 5. The results are discussed in the light of the possible role of the nucleoside triphosphatase in vivo in nucleo-cytoplasmic ribonucleoprotein translocation. 6. It is proposed that poly(G)-stimulated Mg2+-activated adenosine triphosphatase activity should be adopted as an enzymic marker for the nuclear envelope.

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“…Both, x 100,000. evidence presented , at least for the RNase digestion , is far from being clear-cut. The annular particles also are reported as sites of special ATPa se activity (89)(90)(91). As Watson (8 I) first noted a close relationship of the annular s ubunits to the cytoplasmic polysomes in the pore vicinity is obvious in numero us plant and animal cells.…”

Section: 58 63)mentioning

confidence: 99%

The ultrastructure of the nuclear envelope of amphibian oocytes: a reinvestigation I. The mature oocyte

Franke

Scheer

1970

Journal of Ultrastructure Research

142

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1 n order to review the contradictory statements on the ultrast ru cture o f the nuclear envelope, a study was undertaken combining section and negat ive stai ning electron microscopy on manually isolated oocyte nuclei and nuclear envelopes from six amphibian species including Anura as well as Urodela.The a ppeara nce of the negatively stained iso lated nuclear envelopes is described in deta il a nd the dependence on the preparation co nditio ns used is emphas ized . Pore complex structures such as pore perimeter, centra l granule, an nul ar components, interna l fibrils , a nd annu lus-attached fibril s could be identified by both techniques, negat ive staining a nd sect ions.Comparati ve studies show that no marked diffe rences ex ist in the structural data of the nuclear envelope among the investigated amphibians and the significance of the structura l components is discussed. A model of the nuclea r po re complex based o n the findings of the present investigation is prese nted.To o btai n a n in sight into the mech a ni s ms invol ved in nucl eocyto pl asm ic interactio n, a thorough knowledge of the exchange sites of macromolecules between th ese two compartments is a prior condition. Since Calla n a nd Tomlin (1/) have shown that th e nuclear envelope is interrupted by di scontinuities of co nsta nt size a nd cha racteristi c structura l features, it is wid ely accepted that s uch nucl ear "pore co mpl exes" (80) a re th e gateways through which nucleocyto plasmic interactio ns c hiefl y take place. This is at least in line with the evidence hith erto acc umul a ted (fo r reviews, see e.g., 32, 7/). Co nsiderabl e research on the structure a nd function of th e nucl ear membra ne has been concerned with oocytes, part icula rl y with a mphibi a n oocy tes (20 , 29-34, 36, 37, 43, 55, 64, 66, 74, 79, 82, 84). Despite the large number of ultrastr uctura l studies o n the nuclear pore complex, there ex ist ma ny as toni shing ly diverse model s describin g the spati a l and functional relationship o f th e a nnulus a nd the membra nes limiting th e nuclear pores (e.g., 2, 5, 32, 34, 43, 55, 62, 68, 77,8 1, 82). Furthermore, recent articles (e.g., 33, 34) on structura l d eta il s of the a mphibian oocyte nuclear pore

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The fine structure of nuclei as revealed by electron microscopy

Cited by 77 publications

References 27 publications

Evidence for an Amino Acid Transport System in Nuclei Isolated from Embryonic Heart

Evidence for an Amino Acid Transport System in Nuclei Isolated from Embryonic Heart

Ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. A possible enzymic marker for the nuclear envelope

The ultrastructure of the nuclear envelope of amphibian oocytes: a reinvestigation I. The mature oocyte

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