scholarly journals The folding and unfolding behavior of ribonuclease H on the ribosome

2020 ◽  
Author(s):  
Madeleine K. Jensen ◽  
Avi J. Samelson ◽  
Annette Steward ◽  
Jane Clarke ◽  
Susan Marqusee
Keyword(s):  
Ribosomal Proteins ◽  
Profile Analysis ◽  
Rnase H ◽  
Folding Intermediate ◽  
Folding Rate ◽  
Nascent Chain ◽  
Force Profile ◽  
A Cell ◽  
The Stability ◽  
Pulse Proteolysis

ABSTRACTThe health of a cell depends on accurate translation and proper protein folding; misfolding can lead to aggregation and disease. The first opportunity for a protein to fold occurs during translation, when the ribosome and surrounding environment can affect the energy landscape of the nascent chain. However, quantifying these environmental effects is challenging due to the ribosomal proteins and rRNA, which preclude most spectroscopic measurements of protein energetics. We have applied two gel-based approaches, pulse proteolysis and force-peptide arrest assays, to probe the folding and unfolding pathways of RNase H ribosome-stalled nascent chains. We find that ribosome-stalled RNase H has an increased unfolding rate compared to free RNase H, which completely accounts for observed changes in protein stability and indicates that the folding rate is unchanged. Using arrest peptide-based force-profile analysis, we assayed the force generated during the folding of RNase H on the ribosome. Surprisingly, we find that population of the RNase H folding intermediate is required to generate sufficient force to release the SecM stall and that readthrough of the stall sequence directly correlates with the stability of the folding intermediate. Together, these data imply that the folding pathway of RNase H is unchanged on the ribosome. Furthermore, our data indicate that the ribosome promotes unfolding while the nascent chain is proximal to the ribosome, which may limit the deleterious effects of misfolding and assist in folding fidelity.

scholarly journals The folding and unfolding behavior of ribonuclease H on the ribosome

2020 ◽  
Vol 295 (33) ◽  
pp. 11410-11417 ◽  
Author(s):  
Madeleine K. Jensen ◽  
Avi J. Samelson ◽  
Annette Steward ◽  
Jane Clarke ◽  
Susan Marqusee
Keyword(s):  
Protein Stability ◽  
Ribosomal Proteins ◽  
Profile Analysis ◽  
Rnase H ◽  
Folding Intermediate ◽  
Folding Rate ◽  
Nascent Chain ◽  
Force Profile ◽  
Pulse Proteolysis

The health of a cell depends on accurate translation and proper protein folding, whereas misfolding can lead to aggregation and disease. The first opportunity for a protein to fold occurs during translation, when the ribosome and surrounding environment can affect the nascent chain energy landscape. However, quantifying these environmental effects is challenging because ribosomal proteins and rRNA preclude most spectroscopic measurements of protein energetics. Here, we have applied two gel-based approaches, pulse proteolysis and force-profile analysis, to probe the folding and unfolding pathways of RNase H (RNH) nascent chains stalled on the prokaryotic ribosome in vitro. We found that ribosome-stalled RNH has an increased unfolding rate compared with free RNH. Because protein stability is related to the ratio of the unfolding and folding rates, this increase completely accounts for the observed change in protein stability and indicates that the folding rate is unchanged. Using arrest peptide–based force-profile analysis, we assayed the force generated during the folding of RNH on the ribosome. Surprisingly, we found that population of the RNH folding intermediate is required to generate sufficient force to release a stall induced by the SecM stalling sequence and that readthrough of SecM directly correlates with the stability of the RNH folding intermediate. Together, these results imply that the folding pathway of RNH is unchanged on the ribosome. Furthermore, our findings indicate that the ribosome promotes RNH unfolding while the nascent chain is proximal to the ribosome, which may limit the deleterious effects of RNH misfolding and assist in folding fidelity.

scholarly journals Gradual compaction of the nascent peptide during cotranslational folding on the ribosome

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Marija Liutkute ◽  
Manisankar Maiti ◽  
Ekaterina Samatova ◽  
Jörg Enderlein ◽  
Marina V Rodnina
Keyword(s):  
Profile Analysis ◽  
Dynamic Properties ◽  
Correlation Spectroscopy ◽  
Hydrophobic Core ◽  
Fluorescence Correlation ◽  
Nascent Peptide ◽  
Nascent Chain ◽  
Force Profile ◽  
Exit Tunnel ◽  
Domain Stabilization

Nascent polypeptides begin to fold in the constrained space of the ribosomal peptide exit tunnel. Here we use force-profile analysis (FPA) and photo-induced energy-transfer fluorescence correlation spectroscopy (PET-FCS) to show how a small α-helical domain, the N-terminal domain of HemK, folds cotranslationally. Compaction starts vectorially as soon as the first α-helical segments are synthesized. As nascent chain grows, emerging helical segments dock onto each other and continue to rearrange at the vicinity of the ribosome. Inside or in the proximity of the ribosome, the nascent peptide undergoes structural fluctuations on the µs time scale. The fluctuations slow down as the domain moves away from the ribosome. Mutations that destabilize the packing of the domain’s hydrophobic core have little effect on folding within the exit tunnel, but abolish the final domain stabilization. The results show the power of FPA and PET-FCS in solving the trajectory of cotranslational protein folding and in characterizing the dynamic properties of folding intermediates.

scholarly journals Gradual Compaction of the Nascent Peptide During Cotranslational Folding on the Ribosome

2020 ◽  
Author(s):  
Marija Liutkute ◽  
Manisankar Maiti ◽  
Ekaterina Samatova ◽  
Jörg Enderlein ◽  
Marina V. Rodnina
Keyword(s):  
Profile Analysis ◽  
Dynamic Properties ◽  
Correlation Spectroscopy ◽  
Fluorescence Correlation ◽  
Cotranslational Folding ◽  
Nascent Peptide ◽  
Nascent Chain ◽  
Force Profile ◽  
Exit Tunnel ◽  
Domain Stabilization

ABSTRACTNascent polypeptides begin to fold in the constrained space of the ribosomal peptide exit tunnel. Here we use force profile analysis (FPA) and photo-induced energy-transfer fluorescence correlation spectroscopy (PET-FCS) to show how a small α-helical domain, the N-terminal domain of HemK, folds cotranslationally. Compaction starts vectorially as soon as the first α-helical segments are synthesized. As nascent chain grows, emerging helical segments dock onto each other and continue to rearrange at the vicinity of the ribosome. Inside or in the proximity of the ribosome, the nascent peptide undergoes structural fluctuations on the μs time scale. The fluctuations slow down as the domain moves away from the ribosome. Folding mutations have little effect on folding within the exit tunnel, but abolish the final domain stabilization. The results show the power of FPA and PET-FCS in solving the trajectory of cotranslational protein folding and in characterizing the dynamic properties of folding intermediates.

scholarly journals Cotranslational folding cooperativity of contiguous domains of α-spectrin

2019 ◽  
Author(s):  
Grant Kemp ◽  
Ola B. Nilsson ◽  
Pengfei Tian ◽  
Robert B. Best ◽  
Gunnar von Heijne
Keyword(s):  
Profile Analysis ◽  
Full Length ◽  
Protein Chain ◽  
Multidomain Proteins ◽  
Cotranslational Folding ◽  
Nascent Chain ◽  
Force Profile ◽  
Biochemical Measurements ◽  
Dynamics Simulations

AbstractProteins synthesized in the cell can begin to fold during translation before the entire polypeptide has been produced, which may be particularly relevant to the folding of multidomain proteins. Here, we study the cotranslational folding of adjacent domains from the cytoskeletal protein α-spectrin using Force Profile Analysis (FPA). Specifically, we investigate how the cotranslational folding behavior of the R15 and R16 domains are affected by their neighboring R14 and R16, and R15 and R17 domains, respectively. Our results show that the domains impact each other’s folding in distinct ways that may be important for the efficient assembly of α-spectrin, and may reduce its dependence on chaperones. Furthermore, we directly relate the experimentally observed yield of full-length protein in the FPA assay to the force exerted by the folding protein in pN. By combining pulse-chase experiments to measure the rate at which the arrested protein is converted into full-length protein with a Bell model of force-induced rupture, we estimate that the R16 domain exerts a maximal force on the nascent chain of ∼15 pN during cotranslational folding.SignificanceIn living cells, proteins are produced in a sequential way by ribosomes. This vectoral process allows the growing protein chain to start to fold before translation has been completed. Thereby, cotranslational protein folding can be significantly different than the folding of a full-length protein in isolation. Here we show how structurally similar repeat domains, normally produced as parts of a single long polypeptide, affect the cotranslational folding of their neighbors. This provides insight into how the cell may efficiently produce multidomain proteins, paving the way for future studies in vivo or with chaperones. We also provide an estimated magnitude of the mechanical force on the nascent chain generated by cotranslational folding, calculated from biochemical measurements and molecular dynamics simulations.

scholarly journals Cotranslational folding cooperativity of contiguous domains of α-spectrin

2020 ◽  
Vol 117 (25) ◽  
pp. 14119-14126 ◽  
Author(s):  
Grant Kemp ◽  
Ola B. Nilsson ◽  
Pengfei Tian ◽  
Robert B. Best ◽  
Gunnar von Heijne
Keyword(s):  
Profile Analysis ◽  
Full Length ◽  
Cytoskeletal Protein ◽  
Multidomain Proteins ◽  
Maximal Force ◽  
Cotranslational Folding ◽  
Nascent Chain ◽  
Force Profile ◽  
Bell Model

Proteins synthesized in the cell can begin to fold during translation before the entire polypeptide has been produced, which may be particularly relevant to the folding of multidomain proteins. Here, we study the cotranslational folding of adjacent domains from the cytoskeletal protein α-spectrin using force profile analysis (FPA). Specifically, we investigate how the cotranslational folding behavior of the R15 and R16 domains are affected by their neighboring R14 and R16, and R15 and R17 domains, respectively. Our results show that the domains impact each other’s folding in distinct ways that may be important for the efficient assembly of α-spectrin, and may reduce its dependence on chaperones. Furthermore, we directly relate the experimentally observed yield of full-length protein in the FPA assay to the force exerted by the folding protein in piconewtons. By combining pulse-chase experiments to measure the rate at which the arrested protein is converted into full-length protein with a Bell model of force-induced rupture, we estimate that the R16 domain exerts a maximal force on the nascent chain of ∼15 pN during cotranslational folding.

scholarly journals Force-profile analysis of the cotranslational folding of HemK and filamin domains: Comparison of biochemical and biophysical folding assays

2018 ◽  
Author(s):  
Grant Kemp ◽  
Renuka Kudva ◽  
Andrés de la Rosa ◽  
Gunnar von Heijne
Keyword(s):  
Real Time ◽  
Profile Analysis ◽  
The Other ◽  
Basic Process ◽  
Cotranslational Folding ◽  
Nascent Chain ◽  
Force Profile ◽  
Exit Tunnel ◽  
Ribosome Exit Tunnel ◽  
Different Parts

AbstractWe have characterized the cotranslational folding of two small protein domains of different folds – the a-helical N-terminal domain of HemK and the β-rich FLN5 filamin domain – by measuring the force that the folding protein exerts on the nascent chain when located in different parts of the ribosome exit tunnel (Force-Profile Analysis - FPA), allowing us to compare FPA to three other techniques currently used to study cotranslational folding: real-time FRET, PET, and NMR. We find that FPA identifies the same cotranslational folding transitions as do the other methods, and that these techniques therefore reflect the same basic process of cotranslational folding in similar ways.

scholarly journals Cotranslational folding of alkaline phosphatase in the periplasm of Escherichia coli

2020 ◽  
Author(s):  
Rageia Elfageih ◽  
Alexandros Karyolaimos ◽  
Grant Kemp ◽  
Jan-Willem de Gier ◽  
Gunnar von Heijne ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Wild Type Strain ◽  
Profile Analysis ◽  
E Coli ◽  
Close Proximity ◽  
Cotranslational Folding ◽  
Nascent Chain ◽  
Force Profile ◽  
Translational Arrest ◽  
Strain Background

AbstractCotranslational protein folding studies using Force Profile Analysis, a method where the SecM translational arrest peptide is used to detect folding-induced forces acting on the nascent polypeptide, have so far been limited mainly to small domains of cytosolic proteins that fold in close proximity to the translating ribosome. In this study, we investigate the cotranslational folding of the periplasmic, disulfide bond-containing E. coli protein alkaline phosphatase (PhoA) in a wild-type strain background and a strain background devoid of the periplasmic thiol:disulfide interchange protein DsbA. We find that folding-induced forces can be transmitted via the nascent chain from the periplasm to the polypeptide transferase center in the ribosome, a distance of ~160 Å, and that PhoA appears to fold cotranslationally via at least two disulfide-stabilized folding intermediates. Thus, Force Profile Analysis can be used to study cotranslational folding of proteins in an extra-cytosolic compartment, like the periplasm.

Using FRET to Measure the Time it Takes for a Cell to Destroy a Virus

2019 ◽  
Author(s):  
Candace E. Benjamin ◽  
Zhuo Chen ◽  
Olivia Brohlin ◽  
Hamilton Lee ◽  
Stefanie Boyd ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Rhodamine B ◽  
Virus Like Particle ◽  
A Cell ◽  
Viral Nanoparticles ◽  
The Stability ◽  
Open Question ◽  
Viral Surface ◽  
Fret Pair

<div><div><div><p>The emergence of viral nanotechnology over the preceding two decades has created a number of intellectually captivating possible translational applications; however, the in vitro fate of the viral nanoparticles in cells remains an open question. Herein, we investigate the stability and lifetime of virus-like particle (VLP) Qβ - a representative and popular VLP for several applications - following cellular uptake. By exploiting the available functional handles on the viral surface, we have orthogonally installed the known FRET pair, FITC and Rhodamine B, to gain insight of the particle’s behavior in vitro. Based on these data, we believe VLPs undergo aggregation in addition to the anticipated proteolysis within a few hours of cellular uptake.</p></div></div></div>

Renal epithelial gene expression profile and bismuth-induced resistance against cisplatin nephrotoxicity

2003 ◽  
Vol 22 (10) ◽  
pp. 535-540 ◽  
Author(s):  
Berend T Leussink ◽  
Hans J Baelde ◽  
Thirza M Broekhuizen-van den Berg ◽  
Emile de Heer ◽  
Gijsbert B van der Voet ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Animal Experiments ◽  
Elongation Factor ◽  
Limiting Factor ◽  
Bismuth Salts ◽  
Proximal Tubular ◽  
A Cell ◽  
Induced Apoptosis

Nephrotoxicity is the most important dose-limiting factor in cisplatin based anti-neoplastic treatment. Pretreatment with bismuth salts, used as pharmaceuticals to treat gastric disorders, has been demonstrated to reduce cisplatin-induced renal cell death in clinical settings and during in vivo and in vitro animal experiments. To investigate the genomic basis of this renoprotective effect, we exposed NRK-52E cells, a cell line of rat proximal tubular epithelial origin, to 33 mM Bi3 for 12 hours, which made them resistant to cisplatin-induced apoptosis. Differentially expressed genes in treated and untreated NRK-52E cells were detected by subtraction PCR and microarray techniques. Genes found to be down regulated (0.17 / 0.31-times) were cytochrome c oxidase subunit I, BAR (an apoptosis regulator), heat-shock protein 70-like protein, and three proteins belonging to the translation machinery (ribosomal proteins S7 and L17, and S1, a member of the elongation factor 1-alpha family). The only up-regulated gene was glutathione Stransferase subunit 3A (1.89-times). Guided by the expression levels of these genes, it may be possible to improve renoprotective treatments during anti-neoplastic therapies.

scholarly journals Serotonergic neuron ribosomes regulate the neuroendocrine control of Drosophila development.

2021 ◽  
Author(s):  
Lisa P Deliu ◽  
Deeshpaul Jadir ◽  
Abhishek Ghosh ◽  
Savraj S Grewal
Keyword(s):  
Developmental Delay ◽  
Ribosomal Proteins ◽  
Growth Control ◽  
Prothoracic Gland ◽  
Neuroendocrine Control ◽  
Ribosomal Function ◽  
A Cell ◽  
Animal Growth ◽  
Main Regulator ◽  
Mechanism Of Growth

The regulation of ribosome function is a conserved mechanism of growth control. While studies in single cell systems have defined how ribosomes contribute to cell growth, the mechanisms that link ribosome function to organismal growth are less clear. Here we explore this issue using Drosophila Minutes, a class of heterozygous mutants for ribosomal proteins (Rps). These animals exhibit a delay in larval development caused by decreased production of the steroid hormone ecdysone, the main regulator of larval maturation. We found that this developmental delay is not caused by decreases in either global ribosome numbers or translation rates. Instead, we show that they are due in part to loss of Rp function specifically in a subset of serotonin (5-HT) neurons that innervate the prothoracic gland to control ecdysone production. We found that these 5-HT neurons have defective secretion in Minute animals, and that overexpression of synaptic vesicle proteins in 5-HTergic cells can partially reverse the Minute developmental delay. These results identify a cell-specific role for ribosomal function in the neuroendocrine control of animal growth and development.

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