Mechanisms in Polypeptide Chain Elongation on Ribosomes

Bermek, Engin

doi:10.1016/s0079-6603(08)60267-6

Cited by 47 publications

(17 citation statements)

References 221 publications

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“…Data are representative of three independent experiments. the translocation of the nascent peptide chain from the A-site to the P-site on the ribosome in a GTP-dependent manner (16). The activity of eEF2 in translation is modulated by protein phosphorylation.…”

Section: B)mentioning

confidence: 99%

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C-terminal Src Kinase (Csk)-mediated Phosphorylation of Eukaryotic Elongation Factor 2 (eEF2) Promotes Proteolytic Cleavage and Nuclear Translocation of eEF2

Yao

Liu

et al. 2014

Journal of Biological Chemistry

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Background: The C-terminal Src kinase (Csk) is known as a tumor suppressor, but Src-independent function is unclear. Results: eEF2 is a new protein substrate of Csk. Conclusion: eEF2 phosphorylation and SUMOylation promote its proteolytic cleavage and nuclear localization. Significance: Our findings suggest that a tyrosine kinase can be both a tumor suppressor and a promoter through regulation of different substrate proteins.

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Section: B)mentioning

confidence: 99%

“…Eukaryotic elongation factor 2 (eEF2) is one of the three protein factors involved in polypeptide chain elongation during protein translation (16). The activity of eEF2 in translation is modulated by protein phosphorylation.…”

mentioning

confidence: 99%

C-terminal Src Kinase (Csk)-mediated Phosphorylation of Eukaryotic Elongation Factor 2 (eEF2) Promotes Proteolytic Cleavage and Nuclear Translocation of eEF2

Yao

Liu

et al. 2014

Journal of Biological Chemistry

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“…Finally, like the EF-Tu isolated from a number of eubacteria, the protein from S. platensis may exchange the GDP bound in the EF-Tu . G D P complex with the GDP free in solution [9,26] and this exchange [3H]GDP in solution with unlabelled GDP bound in the EF-Tu . GDP complex was assayed as reported by Worner and Wolf [9] is greatly enhanced by kirromycin (Fig.…”

Section: Resultsmentioning

confidence: 99%

Purification of the elongation factor Tu (EF‐Tu) from the cyanobacterium Spirulina platensis

Tiboni¹,

Ciferri²

1983

European Journal of Biochemistry

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Elongation factor Tu (EF‐Tu) has been purified from the cyanobacterium Spirulina platensis. By gel electrophoresis the Mr of the purified protein appears to be 49000, a value close to that reported for the EF‐Tu isolated from a number of bacteria but higher than that reported for the protein isolated from Escherichia coli (43000). Functionally, however, S. platensis EF‐Tu may replace the E. coli protein in a protein‐synthesizing system in vitro. In addition, its activity is affected by kirromycin, an antibiotic that specifically interacts with eubacterial EF‐Tu.

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“…With EF-Tu, hydrolysis of GTP was found to be followed by conformational changes in the neighborhood of the binding site of the factor for aminoacyl-tRNA [lo]. Since the aminoacyl-tRNA forms a functionally active complex available for protein synthesis with GTP but not with GDP [25] and because the terminal phosphate of GTP interacts in a specific way with the binding site of the factor for nucleotides [31], the GTPjGDP balance has apparently a regulatory significance for the function of EF-Tu as it has for eEF-1.…”

Section: Discussionmentioning

confidence: 99%

“…It has been reported that an eEF-1.GDP complex is formed during the incubation of the factor with this nucleotide and that this complex is, because of a changed eEF-1 conformation, not capable of binding aminoacyl-tRNA [25]. Since GDP results as well as inorganic phosphate from the GTPase activity of the factor found in our experiments, the formation After the preincubation, the factor was made free of unreacted GTP by passage through Sephadex G-25 columns and its phosphorylation was determined (see Materials and Methods).…”

Section: Phosphorylation Of Eef-1 Modulates the Activity Of The Factormentioning

confidence: 99%

Regulation of the activity of eukaryotic peptide elongation factor 1 by autocatalytic phosphorylation

Tuháčková

Ullrichová

Hradec

1985

European Journal of Biochemistry

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Highly purified peptide elongation factor 1 from rabbit reticulocytes liberates the terminal phosphate from [ Y -~~P I G T P and incorporates it into its own protein. Approximately one phosphate residue becomes bound by one molecule of the factor. Only the eEF-lcr subunit of the factor ( M , 53000) becomes phosphorylated as revealed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate followed by autoradiography and by the incubation of [ Y -~~P I G T P with individual subunits of the elongation factor separated by chromatofocusing in the presence of 5 M urea. The phosphorylation also takes place, though to a lesser extent, if the factor is incubated with Na2H32P04, probably due to the presence of endogenous GTP bound in the molecule of the factor. The content of endogenous GTP in various factor preparations was 0.21 -0.43 mol/mol factor. Phosphorylation of the peptide elongation factor is ribosome-independent, acid-labile and apparently autocatalytic since no other proteins are required for this reaction. Preincubation of the factor with GTP or with inorganic phosphate results in the phosphorylation of the factor and is followed by an enhanced binding of phenylalanyl-tRNA to 80s ribosomes in the presence of poly(U). This is accompanied by a dephosphorylation of the factor protein and thus the reversible autophosphorylation of the factor apparently activates its binding site for aminoacyl-tRNA. This is supported by the observation that sodium fluoride, which inhibits the dephosphorylation of the factor, blocks the factor-catalyzed binding of aminoacyl-tRNA to ribosomes. The incorporation of phosphate into factor protein also inhibits the formation of an eEF-1 . GDP complex, which is inactive in protein synthesis. Thus GDP liberated by the GTPase activity of the factor cannot affect its binding site for aminoacyl-tRNA. This may be the other reason for the enhanced activity of the phosphorylated factor. The autocatalytic GTP-dependent phosphorylation of the peptide elongation factor 1 apparently modifies its function and may thus play a regulatory role in protein synthesis.Several cellular functions in mammalian tissues are modulated by reversible protein phosphorylation, which is considered to be a major general mechanism of metabolic regulation [ 11. Many enzymes and also protein-synthesis factors [2 -41 are phosphorylated by different protein kinases, which bind phosphate groups by ester linkages to serine, threonine and tyrosine residues in the protein, and the resulting bond is acid-stable (see [5] for a review).Autophosphorylation occurring in the absence of kinases represents another mechanism of protein phosphorylation. It results in an acid-labile binding of phosphate to histidine or lysine residues by phosphoamide linkage [6, 71. Such a phosphorylating activity, utilizing phosphate liberated from GTP, has been found to be associated with eIF-2 [8].The prokaryotic EF-Tu, a functional analogue of eukaryotic eEF-1, reveals a significant GTPase activity, which is involved in the el...

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Mechanisms in Polypeptide Chain Elongation on Ribosomes

Cited by 47 publications

References 221 publications

C-terminal Src Kinase (Csk)-mediated Phosphorylation of Eukaryotic Elongation Factor 2 (eEF2) Promotes Proteolytic Cleavage and Nuclear Translocation of eEF2

C-terminal Src Kinase (Csk)-mediated Phosphorylation of Eukaryotic Elongation Factor 2 (eEF2) Promotes Proteolytic Cleavage and Nuclear Translocation of eEF2

Purification of the elongation factor Tu (EF‐Tu) from the cyanobacterium Spirulina platensis

Regulation of the activity of eukaryotic peptide elongation factor 1 by autocatalytic phosphorylation

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