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Abstract
Neoplasia is a heritably altered, relatively autonomous growth of tissue. Hepatocarcinogenesis, the pathogenesis of neoplasia in liver, as modeled in the rat exhibits three distinct, quantifiable stages: initiation, promotion, and progression. Simple mutations and/or epigenetic alterations may result in the irreversible stage of initiation. The stage of promotion results from selective enhancement of cell replication and selective inhibition of cellular apoptosis of initiated cells dependent on the genetic and/or epigenetic alterations of the latter. The irreversible stage of progression results from initial karyotypic alterations that evolve into greater degrees of genomic instability. The initial genomic alteration in the transition from promotion to progression may involve primarily epigenetic mechanisms driven by epigenetic and genetic alterations fixed during the stage of promotion.
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Affiliation(s)
- Henry C Pitot
- McArdle Laboratory for Cancer Research, Department of Oncology and Pathology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
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2
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Ohsumi T, Ichimura T, Sugano H, Omata S, Isobe T, Kuwano R. Ribosome-binding protein p34 is a member of the leucine-rich-repeat-protein superfamily. Biochem J 1993; 294 ( Pt 2):465-72. [PMID: 7690545 PMCID: PMC1134477 DOI: 10.1042/bj2940465] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Protein p34 is a non-glycosylated membrane protein characteristic of rough microsomes and is believed to play a role in the ribosome-membrane association. In the present study we isolated cDNA encoding p34 from a rat liver cDNA library and determined its complete amino acid sequence. p34 mRNA is 3.2 kb long and encodes a polypeptide of 307 amino acids with a molecular mass of about 34.9 kDa. Primary sequence analysis, coupled with biochemical studies on the topology, suggested that p34 is a type II signal-anchor protein; it is composed of a large cytoplasmic domain, a membrane-spanning segment and a 38-amino-acid-long luminally disposed C-terminus. The cytoplasmic domain of p34 has several noteworthy structural features, including a region of 4.5 tandem repeats of 23-24 amino acids. The repeated motif shows structural similarity to the leucine-rich repeat which is found in a variety of proteins widely distributed among eukaryotic cells and which potentially functions in mediating protein-protein interactions. The cytoplasmic domain also contains a characteristic hydrophilic region with abundant charged amino acids. These structural regions may be important for the observed ribosome-binding activity of the p34 protein.
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Affiliation(s)
- T Ohsumi
- Department of Biosystem Science, Graduate School of Science and Technology, Niigata University, Japan
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3
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Ichimura T, Shindo Y, Uda Y, Ohsumi T, Omata S, Sugano H. Anti-(p34 protein) antibodies inhibit ribosome binding to and protein translocation across the rough microsomal membrane. FEBS Lett 1993; 326:241-5. [PMID: 8325372 DOI: 10.1016/0014-5793(93)81799-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The p34 protein is a non-glycosylated, integral membrane protein characteristic of rough microsomes and is believed to play a role in the ribosome-membrane association. Here, antibodies directed against p34 were examined as to their inhibitory effect on ribosome binding to and protein translocation across the microsomal membrane. Preincubation of the stripped (ribosome-depleted) membrane with anti-p34 immunoglobulins (IgGs) or their Fab fragments led to more than 80% inhibition of the binding of ribosomes and their large (60S) subunit to the membrane. The inhibition was dependent on the amount of antibodies used, but comparable amounts of IgGs and Fab fragments from nonimmune serum had less effect. The p34 antibodies were also inhibitory for cotranslational translocation of secretory proteins, i.e. placental lactogen and serum albumin, across the membrane. These results suggest that p34 is involved in the binding of ribosomes to the microsomal membrane and that it is in close proximity to the protein translocation site in the microsomal membrane.
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Affiliation(s)
- T Ichimura
- Department of Biosystem Science, Graduate School of Science and Technology, Niigata University, Japan
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4
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Ichimura T, Ohsumi T, Shindo Y, Ohwada T, Yagame H, Momose Y, Omata S, Sugano H. Isolation and some properties of a 34-kDa-membrane protein that may be responsible for ribosome binding in rat liver rough microsomes. FEBS Lett 1992; 296:7-10. [PMID: 1730294 DOI: 10.1016/0014-5793(92)80391-s] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have isolated, by hydroxyapatite chromatography with a non ionic detergent and a high salt concentration, a non-glycosylated, membrane protein with a relative molecular weight of 34 kDa that had previously been found to be a major constituent of the membrane protein fraction showing ribosome-binding activity derived from rat liver rough microsomes (RM). The isolated 34 kDa protein (p34), when incorporated into a liposome model membrane, exhibited significant binding activity toward ribosomes, its binding properties being similar to those observed with intact RM. Immunochemical analyses using antibodies directed against p34 suggested that it is a membrane-embedded RM surface protein, which is specifically localized in ribosome-attached organelles and widely distributed among mammalian tissues. These results would constitute evidence that p34 is a likely candidate for an RM ribosome-binding protein.
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Affiliation(s)
- T Ichimura
- Department of Biosystem Science, Graduate School of Science and Technology, Niigata University, Japan
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5
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Hortsch M, Avossa D, Meyer DI. Characterization of secretory protein translocation: ribosome-membrane interaction in endoplasmic reticulum. J Cell Biol 1986; 103:241-53. [PMID: 3087996 PMCID: PMC2113795 DOI: 10.1083/jcb.103.1.241] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Secretory proteins are synthesized on ribosomes bound to the membrane of the endoplasmic reticulum (ER). After the selection of polysomes synthesizing secretory proteins and their direction to the membrane of the ER via signal recognition particle (SRP) and docking protein respectively, the polysomes become bound to the ER membrane via an unknown, protein-mediated mechanism. To identify proteins involved in protein translocation, beyond the (SRP-docking protein-mediated) recognition step, controlled proteolysis was used to functionally inactivate rough microsomes that had previously been depleted of docking protein. As the membranes were treated with increasing levels of protease, they lost their ability to be functionally reconstituted with the active cytoplasmic fragment of docking protein (DPf). This functional inactivation did not correlate with a loss of either signal peptidase activity, nor with the ability of the DPf to reassociate with the membrane. It did correlate, however, with a loss of the ability of the microsomes to bind ribosomes. Ribophorins are putative ribosome-binding proteins. Immunoblots developed with monoclonal antibodies against canine ribophorins I and II demonstrated that no correlation exists between the protease-induced inability to bind ribosomes and the integrity of the ribophorins. Ribophorin I was 85% resistant and ribophorin II 100% resistant to the levels of protease needed to totally eliminate ribosome binding. Moreover, no direct association was found between ribophorins and ribosomes; upon detergent solubilization at low salt concentrations, ribophorins could be sedimented in the presence or absence of ribosomes. Finally, the alkylating agent N-ethylmaleimide was shown to be capable of inhibiting translocation (beyond the SRP-docking protein-mediated recognition step), but had no affect on the ability of ribosomes to bind to ER membranes. We conclude that potentially two additional proteinaceous components, as yet unidentified, are involved in protein translocation. One is protease sensitive and possibly involved in ribosome binding, the other is N-ethylmaleimide sensitive and of unknown function.
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Hortsch M, Meyer DI. Transfer of secretory proteins through the membrane of the endoplasmic reticulum. INTERNATIONAL REVIEW OF CYTOLOGY 1986; 102:215-42. [PMID: 3021646 DOI: 10.1016/s0074-7696(08)61276-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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7
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Yamaguchi M, Sakai M, Horigome T, Omata S, Sugano H. Reconstitution into liposomes of membrane proteins involved in ribosome binding on rough endoplasmic reticulum. Ribosome-binding capacity. Biochem J 1981; 194:907-13. [PMID: 7306032 PMCID: PMC1162827 DOI: 10.1042/bj1940907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A membrane protein fraction having a high affinity for polyribosomes was isolated from microsomal membranes of rat liver and was incorporated into liposomes made from microsomal lipids to evaluate the polyribosome-binding capacity of the reconstituted liposomes, with the following results. (1) The polyribosome binding to the reconstituted liposomes depended on the amounts of polyribosomes added to the binding mixture. (2) Liposomes made from lipids alone did not bind any polyribosomes. (3) The polyribosome-binding capacity of the reconstituted liposomes was very sensitive to proteolytic enzyme and strongly inhibited by addition of 0.1 mM-aurintricarboxylic acid or by increasing KCl concentration. These results suggest that the binding mechanism of polyribosomes to the reconstituted liposomes is much like that for rough microsomal membrane stripped of endogenous polyribosomes.
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8
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Margulies MM. Release of ribosomes from thylakoids and endoplasmic reticulum with trypsin. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 606:13-9. [PMID: 7353012 DOI: 10.1016/0005-2787(80)90093-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Release by trypsin of chloroplast ribosomes from rough thylakoids of Chlamydomonas reinhardtii was compared with release by trypsin of ribosomes from endoplasmic reticulum of rat liver. Rough thylakoids could be stripped of ribosomes with trypsin. Ribosomes were released as a mixture of polysomes, monosomes, and subunits. Chymotrypsin was much less effective than trypsin. Released ribosomes behaved like intact particles on zone velocity centrifugation, but showed extensive modification of their polypeptides. Stripped thylakoids sedimented as membranes, but also showed extensive modification of their polypeptides. Some ribosomes could be released in polysomes from rough endoplasmic reticulum by trypsin, provided the incubation mixture contained rat liver extract as a source of RNAase inhibitor. In its absence, ribosomes were released predominantly as monosomes, as reported by others. The rat liver extract inhibited release of polysomes from rough thylakoids by trypsin. Thus, the difference in form in which ribosomes are released from thylakoids, and endoplasmic reticulum by trypsin may be due to the high RNAase content of the latter.
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9
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Hawkins HC, Freedman RB. A gel filtration approach to the study of ribosome-membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 558:85-98. [PMID: 497200 DOI: 10.1016/0005-2736(79)90317-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
1. Gel filtration on agarose can be used to investigate ribosome-membrane interactions without exposing the materials to the high, and possibly perturbing, hydrostatic pressures experienced during centrifugation procedures to separate free ribosomes from membrane vesicles. 2. After treatment of microsomes with degranulating agents, degranulated membranes are isolated from Sepharose 2B columns at the void volume, while displaced ribosomes elute at the total column volume. This provides a convenient method for monitoring degranulation in vitro. 3. Centrifugation of rough microsomes or ribosomes into dense pellets or layers, followed by resuspension, leads to preparations which will not pass rapidly or quantitatively through Sepharose 2B columns. 4. Methods are described for the isolation of degranulated microsomes and ribosomes which are eluted rapidly from Sepharose 2B at the void volume and total column volume, respectively. These materials are suitable for the investigation of ribosome-membrane binding in vitro, using a gel filtration separation to monitor binding. 5. Incubation of 3H-labelled ribosomes with degranulated microsomes in vitro, leads to specific binding, demonstrated by the elution of the bound ribosomes at the void volume.
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11
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Ghani QP, Hollenberg M. Poly(adenosine dephosphate ribose) metabolism and regulation of myocardial cell growth by oxygen. Biochem J 1978; 170:387-94. [PMID: 25065 PMCID: PMC1183906 DOI: 10.1042/bj1700387] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Control of the rate of cardiac cell division by oxygen occurs most probably by altering the redox state of a control substance, e.g. NAD(+)right harpoon over left harpoonNADH. NAD(+) (and not NADH) forms poly(ADP-ribose), an inhibitor of DNA synthesis, in a reaction catalysed by poly(ADP-ribose) polymerase. Lower partial pressure of oxygen, which increases the rate of division, would shift NAD(+)-->NADH, decrease poly(ADP-ribose) synthesis, and increase DNA synthesis. Chick-embryo heart cells grown in culture in 20% O(2) (in which they divide more slowly than in 5% O(2)) did exhibit greater poly(ADP-ribose) polymerase activity (+83%, P<0.001) than when grown in 5% O(2). Reaction product was identified as poly(ADP-ribose) by its insensitivity to deoxyribonuclease, ribonuclease, NAD glycohydrolase, Pronase, trypsin and micrococcal nuclease, and by its complete digestion with snake-venom phosphodiesterase to phosphoribosyl-AMP and AMP. Isolation of these digestion products by Dowex 1 (formate form) column chromatography and paper chromatography allowed calculation of average poly(ADP-ribose) chain length, which was 15-26% greater in 20% than in 5% O(2). Thus in 20% O(2) the increase in poly(ADP-ribose) formation results from chain elongation. Formation of new chains also occurs, probably to an even greater degree than chain elongation. Additionally, poly(ADP-ribose) polymerase has very different K(m) and V(max.) values and pH optima in 20% and 5% O(2). These data suggest that poly(ADP-ribose) metabolism participates in the regulation of heart-cell division by O(2), probably by several different mechanisms.
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12
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Isolation of a warfarin binding protein from liver endoplasmic reticulum of Sprague-Dawley and warfarin-resistant rats. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)39949-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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13
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Shore GC, Tata JR. Functions for polyribosome-membrane interactions in protein synthesis. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 472:197-236. [PMID: 329880 DOI: 10.1016/0304-4157(77)90017-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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14
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Lin JC, Farber E. Effect of ribosome stripping procedures on antigenicity and conformation of endoplasmic reticulum membrane. Biochem Biophys Res Commun 1977; 76:1247-52. [PMID: 71146 DOI: 10.1016/0006-291x(77)90989-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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15
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Khawaja JA, Lindholm DB. Synthesis and the puromycin-mediated release of nascent polypeptide chains by reconstructed rough endoplasmic reticulum from rat liver and brain cortex. FEBS Lett 1977; 78:255-60. [PMID: 885248 DOI: 10.1016/0014-5793(77)80318-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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16
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Fujita S, Ogata F, Nakamura J, Omata S, Sugano H. Isolation and characterization of membrane proteins responsible for attachment of polyribosomes to rough microsomal fraction of rat liver. Biochem J 1977; 164:53-66. [PMID: 880237 PMCID: PMC1164757 DOI: 10.1042/bj1640053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A protein fraction which has a high affinity for polyribosomes was isolated from rough microsomal membranes of rat liver. The mode of polyribosome binding to this fraction (R-fraction) was studied by using CsCl equilibrium centrifugation and compared with that for stripped rough microsomal membranes. The following were found. (1) The polyribosome-binding cpacity of the R-fraction was heat-labile and sensitive to trypsin, and was suppressed by increasing KCl concentration and addition of 0.1 mM-aurintricarboxylic acid. (2) Of the four subfractions obtained by gel filtration of the R-fraction on a Sephadex G-200, only the R1-fraction, eluted at the void volume, showed a high affinity for polyribosomes. The polyribosome-binding capacity of the R1-fraction decreased with time on storage at 4 degrees C. (3) The R1-fraction contained three major proteins with mol. wts. 108,000, 99,000 and 65,000.
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17
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Alam SN, Shires TK. The labeling of polysomes and rough microsomal membranes by 5-fluoroorotic acid. Biochem Biophys Res Commun 1977; 74:1441-9. [PMID: 843370 DOI: 10.1016/0006-291x(77)90603-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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18
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McIntosh PR, O'Toole K. The interaction of ribosomes and membranes in animal cells. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 457:171-212. [PMID: 823979 DOI: 10.1016/0304-4157(76)90010-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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19
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Davis JL, Morris RO. The affinity of rat liver ribosome subunits for degranulated rough microsomal membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 443:437-42. [PMID: 963065 DOI: 10.1016/0005-2736(76)90463-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Potassium and magnesium ion concentrations affected the extent but not the specificity of binding in vitro of 60-S and 40-S ribosome subunits to degranulated rough microsomal membranes from rat liver. Scatchard plots revealed that under ionic conditions most likely to resemble those in vivo, the affinity constants for binding 60-S subunits were approximately four-times greater than those characterizing 40-S subunit binding. Further, the extent to which subunits bound at saturation was close to the level of ribosomes present in intact membranes.
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Dani HM, Fielder JA, Rabin BR. Degranulation and sex-specific regranulation of reticular membranes from rat liver as studied using a spectrophotometric assay of protein disulphide isomerase. FEBS Lett 1976; 65:377-82. [PMID: 955073 DOI: 10.1016/0014-5793(76)80151-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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21
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Shires TK. Inhibition by lipoperoxidation of amino acid incorporation by rough microsomal membranes in vitro and its partial reversibility. Arch Biochem Biophys 1975; 171:695-7O7. [PMID: 969 DOI: 10.1016/0003-9861(75)90082-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Schiaffonati L, Cajone F, Bernelli-Zazzera A. Interactions of liver encoplasmic reticulum membranes and polysomes in vitro. J Membr Biol 1975; 21:11-24. [PMID: 1195333 DOI: 10.1007/bf01941059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The interactions of various preparations of endoplasmic reticulum membranes and polysomes have been studied by means of a sandwich sucrose gradient that clearly isolates free ribosomes, smooth endoplasmic reticulum (S.E.R.) and rough endoplasmic reticulum (R.E.R.) from the microsomal fraction of rat liver homogenates. Reconstructed rough membranes separate well from the native R.E.R. but occupy the same position along the gradient as the S.E.R. and the rough membranes, stripped of their ribosomes by means of LiCl. Native R.E.R. and S.E.R. do not bind any added labeled polysomes at 0 degree C; previous treatment with LiCl does not modify the behavior of S.E.R. The presence of cell sap during the binding reaction does not increase polysome fixation by stripped-rough membranes but protects in some way the polysomes and preserves all their original functional capacity of amino acid incorporation into protein.
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Pestana A, Pitot HC. Acetylation of ribosome-associated proteins in vitro by an acetyltransferanse bound to rat liver ribosomes. Biochemistry 1975; 14:1397-403. [PMID: 235951 DOI: 10.1021/bi00678a009] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Incubation of rat liver ribosomes with [1-14-C]acetyl-coenzyme A results in the incorporation of [14-C]acetyl into a material insoluble in cold trichloroacetic acid. The acetyltransferase involved in the self-acetylation of ribosomes can be released by high salt washing of the ribosomes; the activity of the solubilized enzyme can be assayed using histones as acetyl acceptors. Electrophoretic analysis of acetylated risosomes or ribosomal proteins indicated that the acetyl radicals are associated with a group of relatively basic proteins, having molecular weights ranging from 10,000 to 45,000. Chromatographic analysis of the enzymatic hydrolsates of proteins extracted from acetylated ribosomes indicates that acetylation is mainly or exclusively NH2 terminal. Almost 80% of the acetyl proteins are released from the ribosomes by high salt treatment. Most of the acetyl radicals not solubilized by the high salt treatment were found in the 60S subunit, associated with a protein(s) having an apparent molecular weight of 43,000. This acetyl protein(s) was released from the 60S subunit by EDTA treatment and was found in a ribonucleoprotein complex having a bouyant density of 1.56.
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Brightwell MD, Leech CE, O'Farrell MK, Whish WJ, Shall S. Poly(adenosine diphosphate ribose) polymerase in Physarum polycephalum. Biochem J 1975; 147:119-29. [PMID: 239697 PMCID: PMC1165381 DOI: 10.1042/bj1470119] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. The isolated nuclei of the slime mould Physarum polycephalum contain an enzyme that will incorporated [adenine-3H] NAD+ into an acid-insoluble product, which is shown to be poly(ADP-ribose). 2. This incorporation has an optimum pH of 8.2 and a temperature optimum below 10degreesC. 3. Optimum stimulation is given by 15 mM-Mg2+. 4. 2-Mercaptoethanol or dithiothreitol also stimulates the incorporation, the latter at an optimum concentration of about 1 mM. 5. Under optimum conditions the Km value for the reaction is 0.28 mM at 15degreesC. Nicotinamide inhibits the incorporation with a Ki of 5.7 muM. 6. Exogenous DNA stimulates the incorporation by about 100%. 7. Preincubation of the nuclei with deoxyribonuclease, but not with ribonuclease, almost completely inactivates the incorporation of NAD+. 8. The enzyme is unstable at both 0degrees and 15degreesC in the absence of dithiothreitol. The presence of dithiothreitol at a concentration of 1 mM stabilizes the enzyme at both these temperatures. 9. The activity of this enzyme per nucleus was shown in three separate experiments to fall by about one-half in early S phase and then to rise to its pre-mitotic value after about 3 h, that is in late S phase. 10. The possible physiological function of this enzyme system is discussed.
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Kellems RE, Allison VF, Butow RA. Cytoplasmic type 80S ribosomes associated with yeast mitochondria. IV. Attachment of ribosomes to the outer membrane of isolated mitochondria. J Cell Biol 1975; 65:1-14. [PMID: 1092698 PMCID: PMC2111154 DOI: 10.1083/jcb.65.1.1] [Citation(s) in RCA: 227] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Growing yeast spheroplasts were shown to have, on the average, four times the number of cytoplasmic ribosomes in contact with the outer mitochondrial membrane compared to starved spheroplasts. Ribosomes in contact with mitochondria in the growing spheroplast preparation, like free cytoplasmic ribosomes, exist primarily as polysome structures. In the starved spheroplast preparation, both mitochondria-bound and free cytoplasmic ribosomes exist primarily as monosomes. Mitochondria isolated from growing spheroplasts in a medium containing lmM Mg++ have cytoplasmic ribosomes bound directly to the outer membrane. These ribosomes can be quantitatively removed by washing the mitochondria with 2 mM EDTA. Mitochondria from starved spheroplasts are capable of accepting either free cytoplasmic polysomes or cytoplasmic polysomes extracted from mitochondria. However, the extent of polysome binding to mitochondria was shown to be a direct function of the Mg++ concentration; a smaller percentage of the input polysomes bind as the Mg++ concentration is lowered. At 1 mM Mg++, neither free cytoplasmic nor mitochondria-bound polysomes bind to mitochondria. Nevertheless, when growing spheroplasts are broken and mitochondria isolated in medium containing 1 mM Mg++, the mitochondria are seen to have cytoplasmic ribosomes firmly attached to the outer membrane. This result, in addition to our earlier data (Kellems, R. E., and R. A. Butow. 1974. J. Biol. Chem. 249:3304-3310), support the view that cytoplasmic ribosomes attached to the outer membrane of purified mitochondria were attached in vivo. In preparations of mitochondria isolated from growing spheroplasts, ribosomes appear to be found to specific regions of the outer membrane, namely those regions which are in close association or in contact with the inner mitochondrial membrane. This is particularly evident with mitochondria in a condensed configuration. This finding suggests a mechanism whereby cytoplasmically synthesized mitochondrial protein could be transferred by a process of vectorial translation across both membranes of the organelle.
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Shires TK, McLaughlin CM, Pitot HC. The selectivity and stoicheiometry of membrane binding sites for polyribosomes, ribosomes and ribosomal subunits in vitro. Biochem J 1975; 146:513-26. [PMID: 167719 PMCID: PMC1165340 DOI: 10.1042/bj1460513a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Differences in the binding sites for polyribosomes, template-depleted ribosomes and large ribosomal subunits were found in microsomal derivatives of the rough endoplasmic reticulum. 1. The stoicheiometry of polyribosome and ribosome interaction in vitro with membranes was shown to be influenced by the relative concentration of interactants and the duration of their mixing. Large ribosomal subunits required a more prolonged mixing schedule to achieve saturation of membranes than did polyribosomes. 2. By using a procedure which minimized the effects on binidng by the stoicheiometric variables, competition between populations of polyribosomes, ribosomes and subunits for membrane sites showed that subunits, and to a lesser extent ribosomes, failed to block polyribosome attachment. 3. Polyribosomes isolated from liver, kidney and hepatoma 5123C entirely bound to a common membrane site, but some polyribosomes from myeloma MOPC-21 bound to other sites, perhaps influenced by their unique nascent proteins. 4. Subunit-binding sites appear on rough membranes only after endogenous polyribosomes have been removed, but no evidence that resulting changes in surface constituents are responsible was found. Large-subunit binding was largely abolished by lowering MgC12 concentration of 0.1 mM, whereas under the same conditions polyribosome binding was undiminished. 5. The large-subunit site appears to be distinct from the polyribosome site not only in the restriction of its affinity for particles but also spatially, to the extent that bound subunits do not hinder access of polyribosomes to their sites.
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Sabatini DD, Ojakian G, Lande MA, Lewis J, Mok W, Adesnik M, Kreibich G. Structural and functional aspects of the protein synthesizing apparatus in the rough endoplasmic reticulum. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1975; 62:151-80. [PMID: 1106131 DOI: 10.1007/978-1-4684-3255-8_9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Shires TK, Ekren T, Hinderaker P, Pitot HC. Effect of ribosome removal of rough microsomal composition and polysome attachment in vitro. Comparison of liver and kidney. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 374:59-75. [PMID: 4429741 DOI: 10.1016/0005-2787(74)90199-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Borgese N, Mok W, Kreibich G, Sabatini DD. Ribosomal-membrane interaction: in vitro binding of ribosomes to microsomal membranes. J Mol Biol 1974; 88:559-80. [PMID: 4449120 DOI: 10.1016/0022-2836(74)90408-2] [Citation(s) in RCA: 151] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Cajone F, Schiaffonati L, Piccoletti R, Bernelli-Zazzera A. Ribosome-membrane relationships in ischemic livers. Exp Mol Pathol 1974; 21:40-51. [PMID: 4424228 DOI: 10.1016/0014-4800(74)90077-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Rolleston FS. Dissociation constant of 60S ribosomal subunit binding to endoplasmic reticulum membranes. Biochem Biophys Res Commun 1974; 59:467-73. [PMID: 4851405 DOI: 10.1016/s0006-291x(74)80003-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Takagi M, Hoagland MB. Polysome-binding capacity of membranes in the cytoplasmic extract prepared from phenobarbital treated and regenerating rat liver. Biochem Biophys Res Commun 1974; 58:868-75. [PMID: 4836279 DOI: 10.1016/s0006-291x(74)80497-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Jothy S, Champsaur H, Simpkins H. Structural changes in rat liver endoplasmic reticulum following triiodothyronine administration. Biochimie 1974; 56:115-8. [PMID: 4367851 DOI: 10.1016/s0300-9084(74)80361-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Pestana A, Pitot HC. N-terminal acetylation of histone-like nascent peptides on rat liver polyribosomes in vitro. Nature 1974; 247:200-2. [PMID: 4810424 DOI: 10.1038/247200a0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Mills ES, Jones AL. Ultrastructural concepts of drug metabolism. II. The hepatocyte: phenobarbital and microsomal enzyme induction. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 1974; 1:271-98. [PMID: 4219714 DOI: 10.3109/00952997409040872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Shires TK, Pitot HC. The membron: a functional hypothesis for the translational regulation of genetic expression. BIOMEMBRANES 1974; 5:81-145. [PMID: 4603228 DOI: 10.1007/978-1-4684-7389-6_3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Scott-Burden T, Hawtray AO. The effect of neuraminidase treatment of ribosome-free membranes on their ribosomal reattachment ability. Biochem Biophys Res Commun 1973; 54:1288-95. [PMID: 4356813 DOI: 10.1016/0006-291x(73)91127-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Simpkins H, Panko E, Tay S. A comparative study of ribonuclease hydrolysis of rat brain-cortex and liver membrane-bound ribosomes. Biochem J 1973; 135:299-305. [PMID: 4764263 PMCID: PMC1165823 DOI: 10.1042/bj1350299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Because it has been proposed that the ribosome-membrane interaction is different in endoplasmic reticulum derived from a non-secretory and secretory cell we undertook a study to determine whether attachment of the ribosome to the membrane involved ribosomal RNA and if the rRNA in ribosomes derived from the two classes of cell possessed an altered susceptibility to RNAase (ribonuclease) hydrolysis. We found that brain ribosomes appeared to possess more regions accessible to nuclease attack, independent of whether a sequence-dependent RNAase (T(1)) or a sterically hindered RNAase bound to Enzite polymer was employed. These results were independent of whether the ribosomes were membrane-bound or detached from the endoplasmic reticulum membranes, but at high RNAase concentration these differences became negligible. No conclusions, however, could be drawn as to whether ribosomal RNA is involved in the attachment of the ribosome to the endoplasmic reticulum membrane, because of the presence of endogeneous membrane-associated RNAases. Analysis of the rRNA fragments by polyacrylamide-gel electrophoresis suggests that the sites available for attack by low concentrations of nuclease in bound-ribosomes derived from brain cortex are different from those of liver.
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Ekren T, Shires T, Pitot HC. Determining the affinity in vitro of hepatic ribosomal subunits for derivatives of the rough endoplasmic reticulum. Biochem Biophys Res Commun 1973; 54:283-9. [PMID: 4741567 DOI: 10.1016/0006-291x(73)90920-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Kubota K, Yamaki H, Nishimura T. Functional interaction of free polyribosomes with the membrane of the endoplasmic reticulum in a cell-free protein-synthesizing system from plasmacytoma X5563. Biochem Biophys Res Commun 1973; 52:489-95. [PMID: 4711165 DOI: 10.1016/0006-291x(73)90738-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Shires TK, Ekren T, Narurkar LM, Pitot HC. Protein synthesis on rat liver polysome-membrane complexes formed in vitro and disposition of the discharges chains. NATURE: NEW BIOLOGY 1973; 242:198-201. [PMID: 4512933 DOI: 10.1038/newbio242198a0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Burke GT, Redman CM. The distribution of radioactive peptides synthesized by polysomes and ribosomal subunits combined in vitro with microsomal membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 299:312-24. [PMID: 4706455 DOI: 10.1016/0005-2787(73)90355-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Jothy S, Tay S, Simpkins H. The role of membrane phospholipids in the interaction of ribosomes with endoplasmic-reticulum membrane. Biochem J 1973; 132:637-40. [PMID: 4724594 PMCID: PMC1177629 DOI: 10.1042/bj1320637] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It is shown that the ionic head groups of the membrane phospholipids cannot be solely responsible for the attachment of the ribosome and that other membrane components must also be involved in the binding process.
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Shires TK, Pitot HC. Correlation of rat liver membrane binding of polysomes in vitro with function of the complexes formed. Biochem Biophys Res Commun 1973; 50:344-51. [PMID: 4689052 DOI: 10.1016/0006-291x(73)90846-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Shires TK, Pitot HC. Functional studies of polysome-membrane interactions in vitro. ADVANCES IN ENZYME REGULATION 1973; 11:255-72. [PMID: 4363200 DOI: 10.1016/0065-2571(73)90019-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Mishra RK, Wheldrake JF, Feltham LA. Adrenocorticoids and RNA metabolism in kidney. I. Effect of adrenalectomy on RNA turnover in various subcellular fractions of rat kidney. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 287:106-12. [PMID: 4347124 DOI: 10.1016/0005-2787(72)90334-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Hochberg AA, Stratman FW, Zahlten RN, Morris HP, Lardy HA. Binding of rat liver and hepatoma polyribosomes to stripped rough endoplasmic reticulum in vitro. Biological or an artifact? Biochem J 1972; 130:19-25. [PMID: 4347780 PMCID: PMC1174296 DOI: 10.1042/bj1300019] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Exposed thiol groups do not appear to be related to the binding of (32)P-labelled polyribosomes to stripped rough endoplasmic reticulum in vitro. Treating stripped rough endoplasmic reticulum with GSSG did not diminish binding of polyribosomes, suggesting that binding in vitro has no correlation with the inhibition of protein synthesis in vitro reported by Kosower et al. (1971). Thiol reagents, which are known to dissociate ribosomes, did not significantly decrease binding of (32)P-labelled polyribosomes to stripped rough endoplasmic reticulum. Denaturing the protein of (32)P-labelled polyribosomes or stripped rough endoplasmic reticulum of liver or hepatoma with heat, trichloroacetic acid, or HClO(4) did not alter the binding in vitro. Therefore, the practice of measuring the binding of (32)P-labelled polyribosomes to stripped rough endoplasmic reticulum in vitro (Shires et al., 1971b) is an unsuitable indicator of biological significance in the intact cell.
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Mishra RK, Wheldrake JF, Feltham LA. RNA turnover in endoplasmic reticulum-bound and free ribosomes. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 281:393-5. [PMID: 4639281 DOI: 10.1016/0005-2787(72)90453-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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