Role of protein synthesis in drought resistance

1970 ◽  
Vol 48 (6) ◽  
pp. 1235-1241 ◽  
Author(s):  
P. A. Henckel
Keyword(s):  
Protein Synthesis ◽  
Drought Resistance ◽  
Ribonucleic Acid ◽  
Messenger Rna ◽  
High Energy ◽  
Increased Temperature ◽  
Drought Resistant ◽  
N Incorporation ◽  
Corn Plants

One of the major protective adaptations of plants in response to drought is their ability to renew proteins during drought and to repair themselves rapidly after drought, i.e. after exposure to a combination of increased temperature plus dehydration. Corn plants subjected to presowing hardening were used as a model of plants with increased drought resistance. Such plants have a more drought resistant ultrastructure and form more high-energy substances, which promote synthetic processes in them. In hardened plants, 15N incorporation into proteins during and after drought proceeds at a faster rate than in control plants. Also, their ribonuclease is less active with respect to messenger RNA (ribonucleic acid), and polysome degradation into ribosomes and subunits occurs more slowly during drought. Polysomes revert to normal after drought faster in hardened than in non-hardened plants. All this explains the greater resistance of plants exposed to presowing hardening.

scholarly journals Regulation of mRNA translation in renal physiology and disease

2009 ◽  
Vol 297 (5) ◽  
pp. F1153-F1165 ◽  
Author(s):  
Balakuntalam S. Kasinath ◽  
Denis Feliers ◽  
Kavithalakshmi Sataranatarajan ◽  
Goutam Ghosh Choudhury ◽  
Myung Ja Lee ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Protein Synthesis ◽  
Messenger Rna ◽  
Kidney Injury ◽  
Mrna Translation ◽  
Renal Physiology ◽  
Physiological Adaptation ◽  
Three Stages ◽  
A Site

Translation, a process of generating a peptide from the codons present in messenger RNA, can be a site of independent regulation of protein synthesis; it has not been well studied in the kidney. Translation occurs in three stages (initiation, elongation, and termination), each with its own set of regulatory factors. Mechanisms controlling translation include small inhibitory RNAs such as microRNAs, binding proteins, and signaling reactions. Role of translation in renal injury in diabetes, endoplasmic reticulum stress, acute kidney injury, and, in physiological adaptation to loss of nephrons is reviewed here. Contribution of mRNA translation to physiology and disease is not well understood. Because it is involved in such diverse areas as development and cancer, it should prove a fertile field for investigation in renal science.

scholarly journals Membrane-bound ribosomes of myeloma cells. III. The role of the messenger RNA and the nascent polypeptide chain in the binding of ribosomes to membranes.

1975 ◽  
Vol 67 (1) ◽  
pp. 25-37 ◽  
Author(s):  
B Mechler ◽  
P Vassalli
Keyword(s):  
Protein Synthesis ◽  
Messenger Rna ◽  
Membrane Fraction ◽  
Polypeptide Chain ◽  
Salt Treatment ◽  
Ribosomal Subunits ◽  
Myeloma Cells ◽  
Membrane Bound ◽  
Made In

Mild ribonuclease treatment of the membrane fraction of P3K cells released three types of membrane-bound ribosomal particles: (a) all the newly made native 40S subunits detected after 2 h of [3H]uridine pulse. Since after a 3-min pulse with [35S]methionine these membrane native subunits appear to contain at least sevenfold more Met-tRNA per particle than the free native subunits, they may all be initiation complexes with mRNA molecules which have just become associated with the membranes; (b) about 50% of the ribosomes present in polyribosomes. Evidence is presented that the released ribosomes carry nascent chains about two and a half to three times shorter than those present on the ribosomes remaining bound to the membranes. It is proposed that in the membrane-bound polyribosomes of P3K cells, only the ribosomes closer to the 3' end of the mRNA molecules are directly bound, while the latest ribosomes to enter the polyribosomal structures are indirectly bound through the mRNA molecules; (c) a small number of 40S subunits of polyribosomal origin, presumably initiation complexes attached at the 5' end of mRNA molecules of polyribosomes. When the P3K cells were incubated with inhibitors acting at different steps of protein synthesis, it was found that puromycin and pactamycin decreased by about 40% the proportion of ribosomes in the membrane fraction, while cycloheximide and anisomycin had no such effect. The ribosomes remaining on the membrane fraction of puromycin-treated cells consisted of a few polyribosomes, and of an accumulation of 80S and 60S particles, which were almost entirely released by high salt treatment of the membranes. The membrane-bound ribosomes found after pactamycin treatment consisted of a few polyribosomes, with a striking accumulation of native 60S subunits and an increased number of native 40S subunits. On the basis of the observations made in this and the preceding papers, a model for the binding of ribosomes to membranes and for the ribosomal cycle on the membranes is proposed. It is suggested that ribosomal subunits exchange between free and membrane-bound polyribosomes through the cytoplasmic pool of free native subunits, and that their entry into membrane-bound ribosomes is mediated by mRNA molecules associated with membranes.

The rôle of the nucleolus in ribonucleic acid- and protein synthesis

1961 ◽  
Vol 49 (1) ◽  
pp. 58-63 ◽  
Author(s):  
M. Errera ◽  
A. Hell ◽  
R.P. Perry
Keyword(s):  
Protein Synthesis ◽  
Ribonucleic Acid

The role of the nucleolus in ribonucleic acid- and protein synthesis

1961 ◽  
Vol 49 (1) ◽  
pp. 47-57 ◽  
Author(s):  
R.P. Perry ◽  
A. Hell ◽  
M. Errera
Keyword(s):  
Protein Synthesis ◽  
Ribonucleic Acid

scholarly journals Two proofreading steps amplify the accuracy of genetic code translation

2016 ◽  
Vol 113 (48) ◽  
pp. 13744-13749 ◽  
Author(s):  
Ka-Weng Ieong ◽  
Ülkü Uzun ◽  
Maria Selmer ◽  
Måns Ehrenberg
Keyword(s):  
Protein Synthesis ◽  
Genetic Information ◽  
Molecular Basis ◽  
Messenger Rna ◽  
Ternary Complex ◽  
Elongation Factor ◽  
Elongation Factor Tu ◽  
Substrate Selection ◽  
Gtp Hydrolysis

Aminoacyl-tRNAs (aa-tRNAs) are selected by the messenger RNA programmed ribosome in ternary complex with elongation factor Tu (EF-Tu) and GTP and then, again, in a proofreading step after GTP hydrolysis on EF-Tu. We use tRNA mutants with different affinities for EF-Tu to demonstrate that proofreading of aa-tRNAs occurs in two consecutive steps. First, aa-tRNAs in ternary complex with EF-Tu·GDP are selected in a step where the accuracy increases linearly with increasing aa-tRNA affinity to EF-Tu. Then, following dissociation of EF-Tu·GDP from the ribosome, the accuracy is further increased in a second and apparently EF-Tu−independent step. Our findings identify the molecular basis of proofreading in bacteria, highlight the pivotal role of EF-Tu for fast and accurate protein synthesis, and illustrate the importance of multistep substrate selection in intracellular processing of genetic information.

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