Influence of nascent polypeptide positive charges on translation dynamics

2020 ◽  
Vol 477 (15) ◽  
pp. 2921-2934
Author(s):  
Rodrigo D. Requião ◽  
Géssica C. Barros ◽  
Tatiana Domitrovic ◽  
Fernando L. Palhano
Keyword(s):  
Mrna Decay ◽  
Translation Termination ◽  
Published Data ◽  
Translation Efficiency ◽  
Amino Acid Residues ◽  
High Concentration ◽  
Strong Argument ◽  
Translation Arrest ◽  
Exit Tunnel ◽  
Positively Charged

Protein segments with a high concentration of positively charged amino acid residues are often used in reporter constructs designed to activate ribosomal mRNA/protein decay pathways, such as those involving nonstop mRNA decay (NSD), no-go mRNA decay (NGD) and the ribosome quality control (RQC) complex. It has been proposed that the electrostatic interaction of the positively charged nascent peptide with the negatively charged ribosomal exit tunnel leads to translation arrest. When stalled long enough, the translation process is terminated with the degradation of the transcript and an incomplete protein. Although early experiments made a strong argument for this mechanism, other features associated with positively charged reporters, such as codon bias and mRNA and protein structure, have emerged as potent inducers of ribosome stalling. We carefully reviewed the published data on the protein and mRNA expression of artificial constructs with diverse compositions as assessed in different organisms. We concluded that, although polybasic sequences generally lead to lower translation efficiency, it appears that an aggravating factor, such as a nonoptimal codon composition, is necessary to cause translation termination events.

scholarly journals Rqc1 and other yeast proteins containing highly positively charged sequences are not targets of the RQC complex

2019 ◽  
Author(s):  
Géssica C. Barros ◽  
Rodrigo D. Requião ◽  
Rodolfo L. Carneiro ◽  
Claudio A. Masuda ◽  
Mariana H. Moreira ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Translation Termination ◽  
Ribosome Profiling ◽  
Translation Efficiency ◽  
Ribosome Stalling ◽  
Reporter Systems ◽  
Exit Tunnel ◽  
Endogenous Proteins ◽  
Ribosome Exit Tunnel ◽  
Positively Charged

ABSTRACTHighly positively charged protein segments are known to result in poor translation efficiency. This effect is explained by ribosome stalling caused by electrostatic interactions between the nascent peptide and the negatively charged ribosome exit tunnel, leading to translation termination followed by protein degradation mediated by the RQC complex. These polybasic sequences are mainly studied in the context of artificial reporter systems. Examples of endogenous yeast proteins targeted by the RQC complex are Rqc1, a protein essential for RQC function, and Sdd1. Both contain polybasic sequences that are thought to activate the RQC, leading to protein down-regulation. Here, we investigated whether the RQC complex regulates other endogenous proteins with polybasic sequences. We show by bioinformatics, ribosome profiling data analysis, and western blot that endogenous proteins containing polybasic sequences similar to, or even more positively charged than those of Rqc1 and Sdd1, are not targeted by the RQC complex suggesting that endogenous polybasic sequences are not sufficient to induce this type of regulation. Finally, our results also suggest that Rqc1 is regulated post-translationally by the E3 component of the RQC complex Ltn1, in a manner independent of the RQC complex.

scholarly journals Genome-wide effects of the antimicrobial peptide apidaecin on translation termination in bacteria

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Kyle Mangano ◽  
Tanja Florin ◽  
Xinhao Shao ◽  
Dorota Klepacki ◽  
Irina Chelysheva ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Stop Codon ◽  
Translation Termination ◽  
Bacterial Cells ◽  
Release Factor ◽  
Translation Arrest ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
Exit Tunnel ◽  
Unique Mechanism

Biochemical studies suggested that the antimicrobial peptide apidaecin (Api) inhibits protein synthesis by binding in the nascent peptide exit tunnel and trapping the release factor associated with a terminating ribosome. The mode of Api action in bacterial cells had remained unknown. Here genome-wide analysis reveals that in bacteria, Api arrests translating ribosomes at stop codons and causes pronounced queuing of the trailing ribosomes. By sequestering the available release factors, Api promotes pervasive stop codon bypass, leading to the expression of proteins with C-terminal extensions. Api-mediated translation arrest leads to the futile activation of the ribosome rescue systems. Understanding the unique mechanism of Api action in living cells may facilitate the development of new medicines and research tools for genome exploration.

scholarly journals Genome-wide effects of the antimicrobial peptide apidaecin on translation termination

2020 ◽  
Author(s):  
Kyle Mangano ◽  
Tanja Florin ◽  
Xinhao Shao ◽  
Dorota Klepacki ◽  
Irina Chelysheva ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Stop Codon ◽  
Translation Termination ◽  
Bacterial Cells ◽  
Release Factor ◽  
Translation Arrest ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
Exit Tunnel ◽  
Unique Mechanism

AbstractBiochemical studies suggested that the antimicrobial peptide apidaecin (Api) inhibits protein synthesis by binding in the nascent peptide exit tunnel and trapping the release factor associated with a terminating ribosome. The mode of Api action in bacterial cells had remained unknown. Here, genome-wide analysis revealed that Api arrests translating ribosomes at stop codons and causes pronounced queuing of the trailing ribosomes. By sequestering the available release factors, Api promotes pervasive stop codon bypass, leading to expression of proteins with C-terminal extensions. Api-mediated translation arrest leads to futile activation of the ribosome rescue systems. Understanding the unique mechanism of Api action in living cells may facilitate development of new medicines and research tools for genome exploration.

scholarly journals Species-Specific Regulation of TRPM2 by PI(4,5)P2 via the Membrane Interfacial Cavity

2021 ◽  
Vol 22 (9) ◽  
pp. 4637
Author(s):  
Daniel Barth ◽  
Andreas Lückhoff ◽  
Frank J. P. Kühn
Keyword(s):  
Amino Acid Residues ◽  
Hek 293 ◽  
Complete Inactivation ◽  
293 Cells ◽  
Activation Mechanisms ◽  
Specific Regulation ◽  
Species Specific ◽  
Inside Out ◽  
Positively Charged

The human apoptosis channel TRPM2 is stimulated by intracellular ADR-ribose and calcium. Recent studies show pronounced species-specific activation mechanisms. Our aim was to analyse the functional effect of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), commonly referred to as PIP2, on different TRPM2 orthologues. Moreover, we wished to identify the interaction site between TRPM2 and PIP2. We demonstrate a crucial role of PIP2, in the activation of TRPM2 orthologues of man, zebrafish, and sea anemone. Utilizing inside-out patch clamp recordings of HEK-293 cells transfected with TRPM2, differential effects of PIP2 that were dependent on the species variant became apparent. While depletion of PIP2 via polylysine uniformly caused complete inactivation of TRPM2, restoration of channel activity by artificial PIP2 differed widely. Human TRPM2 was the least sensitive species variant, making it the most susceptible one for regulation by changes in intramembranous PIP2 content. Furthermore, mutations of highly conserved positively charged amino acid residues in the membrane interfacial cavity reduced the PIP2 sensitivity in all three TRPM2 orthologues to varying degrees. We conclude that the membrane interfacial cavity acts as a uniform PIP2 binding site of TRPM2, facilitating channel activation in the presence of ADPR and Ca2+ in a species-specific manner.

Block of Human Heart hH1 Sodium Channels by the Enantiomers of Bupivacaine

2000 ◽  
Vol 93 (4) ◽  
pp. 1022-1033 ◽  
Author(s):  
Carla Nau ◽  
Sho-Ya Wang ◽  
Gary R. Strichartz ◽  
Ging Kuo Wang
Keyword(s):  
Human Heart ◽  
Point Mutations ◽  
Cell Voltage ◽  
Site Directed Mutagenesis ◽  
Na Channel ◽  
Amino Acid Residues ◽  
Na Channels ◽  
State Dependent ◽  
Positively Charged

Background S(-)-bupivacaine reportedly exhibits lower cardiotoxicity but similar local anesthetic potency compared with R(+)-bupivacaine. The bupivacaine binding site in human heart (hH1) Na+ channels has not been studied to date. The authors investigated the interaction of bupivacaine enantiomers with hH1 Na+ channels, assessed the contribution of putatively relevant residues to binding, and compared the intrinsic affinities to another isoform, the rat skeletal muscle (mu1) Na+ channel. Methods Human heart and mu1 Na+ channel alpha subunits were transiently expressed in HEK293t cells and investigated during whole cell voltage-clamp conditions. Using site-directed mutagenesis, the authors created point mutations at positions hH1-F1760, hH1-N1765, hH1-Y1767, and hH1-N406 by introducing the positively charged lysine (K) or the negatively charged aspartic acid (D) and studied their influence on state-dependent block by bupivacaine enantiomers. Results Inactivated hH1 Na+ channels displayed a weak stereoselectivity with a stereopotency ratio (+/-) of 1.5. In mutations hH1-F1760K and hH1-N1765K, bupivacaine affinity of inactivated channels was reduced by approximately 20- to 40-fold, in mutation hH1-N406K by approximately sevenfold, and in mutations hH1-Y1767K and hH1-Y1767D by approximately twofold to threefold. Changes in recovery of inactivated mutant channels from block paralleled those of inactivated channel affinity. Inactivated hH1 Na+ channels exhibited a slightly higher intrinsic affinity than mu1 Na+ channels. Conclusions Differences in bupivacaine stereoselectivity and intrinsic affinity between hH1 and mu1 Na+ channels are small and most likely of minor clinical relevance. Amino acid residues in positions hH1-F1760, hH1-N1765, and hH1-N406 may contribute to binding of bupivacaine enantiomers in hH1 Na+ channels, whereas the role of hH1-Y1767 remains unclear.

scholarly journals Positively charged amino acid residues located similarly in sea anemone and scorpion toxins

1994 ◽  
Vol 269 (24) ◽  
pp. 16785-16788
Author(s):  
E.P. Loret ◽  
R.M. del Valle ◽  
P. Mansuelle ◽  
F. Sampieri ◽  
H. Rochat
Keyword(s):  
Amino Acid ◽  
Sea Anemone ◽  
Amino Acid Residues ◽  
Scorpion Toxins ◽  
Positively Charged

scholarly journals Sequence and Structure of Human Rhinoviruses Reveal the Basis of Receptor Discrimination

2003 ◽  
Vol 77 (12) ◽  
pp. 6923-6930 ◽  
Author(s):  
Marketa Vlasak ◽  
Soile Blomqvist ◽  
Tapani Hovi ◽  
Elizabeth Hewat ◽  
Dieter Blaas
Keyword(s):  
Low Density Lipoprotein ◽  
Three Dimensional ◽  
Density Lipoprotein ◽  
Major Group ◽  
Amino Acid Residues ◽  
X Ray ◽  
Vldl Receptor ◽  
Capsid Protein Vp1 ◽  
Three Dimensional Models ◽  
Positively Charged

ABSTRACT The sequences of the capsid protein VP1 of all minor receptor group human rhinoviruses were determined. A phylogenetic analysis revealed that minor group HRVs were not more related to each other than to the nine major group HRVs whose sequences are known. Examination of the surface exposed amino acid residues of HRV1A and HRV2, whose X-ray structures are available, and that of three-dimensional models computed for the remaining eight minor group HRVs indicated a pattern of positively charged residues within the region, which, in HRV2, was shown to be the binding site of the very-low-density lipoprotein (VLDL) receptor. A lysine in the HI loop of VP1 (K224 in HRV2) is strictly conserved within the minor group. It lies in the middle of the footprint of a single repeat of the VLDL receptor on HRV2. Major group virus serotypes exhibit mostly negative charges at the corresponding positions and do not bind the negatively charged VLDL receptor, presumably because of charge repulsion.

scholarly journals A UPF1 variant drives conditional remodeling of nonsense-mediated mRNA decay

2021 ◽  
Author(s):  
Sarah E. Fritz ◽  
Soumya Ranganathan ◽  
J. Robert Hogg
Keyword(s):  
Gene Expression ◽  
Mrna Decay ◽  
Gene Expression Regulation ◽  
Translation Termination ◽  
Translational Repression ◽  
The Core ◽  
Human Genes ◽  
Rna Quality Control ◽  
Nonsense Mediated Mrna Decay

AbstractThe nonsense-mediated mRNA decay (NMD) pathway monitors translation termination to degrade transcripts with premature stop codons and regulate thousands of human genes. Due to the major role of NMD in RNA quality control and gene expression regulation, it is important to understand how the pathway responds to changing cellular conditions. Here we show that an alternative mammalian-specific isoform of the core NMD factor UPF1, termed UPF1LL, enables condition-dependent remodeling of NMD specificity. UPF1LL associates more stably with potential NMD target mRNAs than the major UPF1SL isoform, expanding the scope of NMD to include many transcripts normally immune to the pathway. Unexpectedly, the enhanced persistence of UPF1LL on mRNAs supports induction of NMD in response to rare translation termination events. Thus, while canonical NMD is abolished by translational repression, UPF1LL activity is enhanced, providing a mechanism to rapidly rewire NMD specificity in response to cellular stress.

scholarly journals Rules for the self-assembly of ESCRT-III on endosomes

2021 ◽  
Author(s):  
Simon Sprenger ◽  
Simona M. Migliano ◽  
Florian Oleschko ◽  
Marvin Kobald ◽  
Michael Hess ◽  
...  
Keyword(s):  
Self Assembly ◽  
Hydrophobic Interactions ◽  
The Self ◽  
Amino Acid Residues ◽  
Lateral Expansion ◽  
Endosomal Sorting ◽  
Aaa Atpase ◽  
Charged Amino Acids ◽  
Membrane Budding ◽  
Positively Charged

ABSTRACTThe endosomal sorting complexes required for transport (ESCRT) mediate various membrane remodeling processes in cells by mechanism that are incompletely understood. Here we combined genetic experiments in budding yeast with site-specific cross-linking to identify rules that govern the self-assembly of individual ESCRT-III proteins into functional ESCRT-III complexes on endosomes. Together with current structural models of ESCRT-III, our findings suggest that, once nucleated, the growing Snf7 protofilament seeds the lateral co-assembly of a Vps24 - Vps2 heterofilament. Both Vps24 and Vps2 use positively charged amino acid residues in their helices α1 to interact with negatively charged amino acids in helix α4 of Snf7 subunits of the protofilament. In the Vps24 - Vps2 heterofilament, the two subunits alternate and interact with each other using hydrophobic interactions between helices α2/α3. The co-assembly of the Vps24 - Vps2 heterofilament restricts the lateral expansion of Snf7 protofilaments and leads the immediate recruitment of the AAA-ATPase Vps4. This self-assembly process of three ESCRT-III subunits results in the formation of a Snf7 protofilament and the co-assembly of a Vps24 - Vps2 heterofilament. This sets the stage for Vps4 recruitment and the subsequent ATP-driven dynamic self-organization of ESCRT-III / Vps4 assemblies and the ensuing membrane budding and scission events.

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