scholarly journals mRNP architecture in translating and stress conditions reveals an ordered pathway of mRNP compaction

2018 ◽  
Author(s):  
Anthony Khong ◽  
Roy Parker

ABSTRACTStress granules (SGs) are non-translating mRNP assemblies that form during stress. Herein, we use multiple smFISH probes for specific mRNAs to examine their SG recruitment and spatial organization. We observed that ribosome run-off is required for SG entry with long ORF mRNAs being delayed in SG accumulation, revealing SG transcriptome changes over time. Moreover, mRNAs are ~20X compacted from an expected linear length when translating and compact ~2 fold further in a stepwise manner beginning at the 5’ end during ribosome run-off. Surprisingly, the 5’ and 3’ ends of the examined mRNAs were separated in non-stress conditions, but in non-translating conditions, the ends of AHNAK and DYNC1H1 mRNAs become close, suggesting the closed-loop model of mRNPs preferentially forms on non-translating mRNAs. These results suggest translation inhibition triggers a mRNP reorganization that brings ends closer, which has implications for the regulation of mRNA stability and translation by 3’ UTR elements and the poly(A) tail.

2018 ◽  
Vol 217 (12) ◽  
pp. 4124-4140 ◽  
Author(s):  
Anthony Khong ◽  
Roy Parker

Stress granules (SGs) are transient membraneless organelles of nontranslating mRNA–protein complexes (mRNPs) that form during stress. In this study, we used multiple single-molecule FISH probes for particular mRNAs to examine their SG recruitment and spatial organization. Ribosome runoff is required for SG entry, as long open reading frame (ORF) mRNAs are delayed in SG accumulation, indicating that the SG transcriptome changes over time. Moreover, mRNAs are ∼20× compacted from an expected linear length when translating and compact ∼2-fold further in a stepwise manner beginning at the 5′ end during ribosome runoff. Surprisingly, the 5′ and 3′ ends of the examined mRNAs were separated when translating, but in nontranslating conditions the ends of long ORF mRNAs become close, suggesting that the closed-loop model of mRNPs preferentially forms on nontranslating mRNAs. Compaction of ribosome-free mRNAs is ATP independent, consistent with compaction occurring through RNA structure formation. These results suggest that translation inhibition triggers an mRNP reorganization that brings ends closer, which has implications for the regulation of mRNA stability and translation by 3′ UTR elements and the poly(A) tail.


VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.


2007 ◽  
Author(s):  
Miranda Olff ◽  
Mirjam Nijdam ◽  
Kristin Samuelson ◽  
Julia Golier ◽  
Mariel Meewisse ◽  
...  

2010 ◽  
Author(s):  
Rebecca D. Stinson ◽  
Zachary Sussman ◽  
Megan Foley Nicpon ◽  
Allison L. Allmon ◽  
Courtney Cornick ◽  
...  

2019 ◽  
Vol 47 (02) ◽  
pp. 133-133

Knowler SP, Gillstedt L, Mitchell TJ et al. Pilot study of head conformation changes over time in the Cavalier King Charles spaniel breed. Veterinary Record 2019. doi:10.1136/vr.105135.


2019 ◽  
Vol 5 (4) ◽  
pp. 410-427 ◽  
Author(s):  
Ryan P. Thombs ◽  
Xiaorui Huang

The macro-comparative decoupling literature has often sought to test the arguments made by the treadmill of production (TP) and ecological modernization (EM) theories. However, due to data limitations, these studies have been limited to analyzing the years after 1960. Given that both theories discuss historical processes operating before 1960, analyzing pre-1960 data is warranted to more comprehensively test the propositions made by both theories. We assess the long-term relationship between economic growth and CO2 emissions from 1870 to 2014 using a sample of global North nations. We use Prais-Winsten regression models with time interactions to assess whether, when, and how much CO2 emissions have decoupled from economic growth over time. We find that significant relative decoupling has occurred twice since 1870: during the last 30 years of the nineteenth century, the timing of which is contrary to what both the EM and TP theories might expect, and after 1970. We also observe that the relationship remained relatively stable from the turn of the twentieth century to approximately 1970, which aligns with the arguments made by the classical TP work. We conclude that shifts in the global organization of production have shaped the magnitude of the economic growth–CO2 emissions relationship and its changes over time, which has implications for climate mitigation policy.


Sign in / Sign up

Export Citation Format

Share Document