The Effects of Steroid Hormones and Carcinogens on the Interaction of Membranes with Polysomes

Rabin, B. R.; Blyth, Carol A.; Doherty, Delma; Freedman, Robert B.; Roobol, Anne; Sunshine, Geoffrey H.; Williams, David

doi:10.1007/978-1-349-01321-0_3

Cited by 5 publications

(2 citation statements)

References 19 publications

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“…To explain differences in specific activities and the effects of detergents and NH3 on smooth and rough microsomes, Stetten & Ghosh (1971) have suggested that gIucose 6-phosphatase is more accessible to substrate in the rough-than in the smooth-microsomal vesicles and that this difference may be due to the presence of ribosomes. In this connection Rabin and co-workers have shown that the presence or the absence of ribosomes affects the activity of the disulphide-interchange enzyme of microsomal membranes (Rabin et al, 1971). Our results may be consistent with such an effect, but with an intrinsic heterogeneity of enzyme distribution within the membrane superimposed on this effect of ribosomes.…”

Section: Explanation Of Platesupporting

confidence: 85%

Heterogeneous distribution of glucose 6-phosphatase in rat liver microsomal fractions as shown by adaptation of a cytochemical technique

Lewis¹,

Tata²

1973

Biochemical Journal

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1. A novel technique for the subfractionation of rat liver smooth and rough microsomal fractions according to their content of glucose 6-phosphatase is described. This technique, based on the Gomori lead histochemical procedure, involves incubation of smooth and rough microsomal fractions with low concentrations of Pb(NO3)2 and glucose 6-phosphate. Control experiments, in which enzyme was assayed in the presence of various amounts of Pb(NO3)2 or in which microsomal fractions were reisolated after incubation with low concentrations of Pb(NO3)2 and glucose 6-phosphate, showed that lead does not interfere with glucose 6-phosphatase activity. 2. Discontinuous sucrose-densitygradient centrifugation of microsomal fractions which had previously been incubated with various amounts of Pb(N03)2 and glucose 6-phosphate showed that it is possible to subfractionate both smooth-and rough-microsomal fractions into several bands, owing to a differential modification of the density of the microsomal vesicles by the trapping of lead phosphate within them. 3. When the material in the bands obtained by density-gradient centrifugation ofincubated microsomal fractions was assayed for glucose 6-phosphatase activity, it was found that the modification of the density ofthe microsomal fractions was directly related to their relative enrichment in glucose 6-phosphatase activity. Control experiments, in which microsomal fractions were incubated with Pb(NO3)2 and glucose 6-phosphate and then treated with EDTA, showed that the subfractionation was not due to aggregation of microsomal vesicles, lead and glucose 6-phosphate. Thus the resolution of microsomal preparations into subfractions with different glucose 6-phosphatase activities is interpreted as indicating heterogeneity of glucose 6-phosphatase distribution in the microsomal vesicles. 4. Electron micrographs of both smooth-and rough-microsomal subfractions show deposits of lead phosphate within the microsomal vesicles. The frequency and extent of these deposits correlate with the different amounts of glucose 6-phosphatase activity measured biochemically. 5. The nature of the heterogeneous distribution of glucose 6-phosphatase is discussed and the more general applicability of the technique for studying membrane fractions containing a heterogeneous distribution of phosphatases is indicated.

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Section: Explanation Of Platesupporting

confidence: 85%

Heterogeneous distribution of glucose 6-phosphatase in rat liver microsomal fractions as shown by adaptation of a cytochemical technique

Lewis¹,

Tata²

1973

Biochemical Journal

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“…The purified enzyme responsible for this activity was also found to catalyze redox isomerization of misfolded proteins, effectively rearranging disulfide bonds to achieve native conformation [1]. Initially called sulfhydryl-disulfide interchange enzyme or 'rearrangease', in 1972 the enzyme commission (EC) assigned the systematic name, protein disulfide isomerase (PDI) (EC 5.3.4.1) [2]. Because PDI was active in microsomes, it was presumed that it has a major role in the ER catalyzing the proper folding of disulfide bond-containing proteins destined for the secretory pathway.…”

Section: Introductionmentioning

confidence: 99%

Dual protein trafficking to secretory and non-secretory cell compartments: Clear or double vision?

2015

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Charman's Closing Remarks

Allison

1978

Novartis Foundation Symposia

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The Effects of Steroid Hormones and Carcinogens on the Interaction of Membranes with Polysomes

Cited by 5 publications

References 19 publications

Heterogeneous distribution of glucose 6-phosphatase in rat liver microsomal fractions as shown by adaptation of a cytochemical technique

Heterogeneous distribution of glucose 6-phosphatase in rat liver microsomal fractions as shown by adaptation of a cytochemical technique

Dual protein trafficking to secretory and non-secretory cell compartments: Clear or double vision?

Charman's Closing Remarks

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