scholarly journals Translational repression by MSY4 inhibits spermatid differentiation in mice

Development ◽  
2002 ◽  
Vol 129 (15) ◽  
pp. 3669-3679
Author(s):  
Flaviano Giorgini ◽  
Holly G. Davies ◽  
Robert E. Braun

In developing male germ cells, newly synthesized protamine mRNAs are stored for up to 7 days before translational activation. Translational repression of protamine 1 (Prm1) mRNA requires sequences present in its 3′ untranslated region (UTR) and substantial evidence suggests a role for the murine Y-box protein MSY4 in this process. To determine if MSY4 can mediate translational repression in vivo, we generated transgenic mice in which the temporal window of MSY4 expression was extended during spermatogenesis. Expression of MSY4 disrupted the normal completion of spermatogenesis and caused dominant sterility. Immunocytochemical analysis of several markers, including the protamines, indicated that MSY4 prevented normal activation of translation. mRNAs whose translation was inhibited contained at least one MSY4 RNA recognition site, suggesting sequence-dependent translational repression. Altered translational activation resulted in defective processing of protamine 2 and severe defects in sperm morphogenesis. These results suggest that MSY4 plays an active role in translational repression of several mRNAs in differentiating spermatids.

2021 ◽  
Author(s):  
Chong Tang ◽  
Mei Guo ◽  
Zhuoxing Shi ◽  
Zhuqing Wang ◽  
Chunhai Luo ◽  
...  

AbstractAs one of the post-transcriptional regulatory mechanisms, transcription and translation’s uncoupling plays an essential role in development and adulthood physiology. However, it remains elusive how thousands of mRNAs get translationally silenced while stability is maintained for up to hours or even days before translation. In addition to oocytes and neurons, developing spermatids have significant uncoupling of transcription and translation for delayed translation. Therefore, spermiogenesis represents an excellent in vivo model for investigating the mechanism underlying uncoupled transcription and translation. Through full-length poly(A) deep sequencing, we discovered dynamic changes in poly(A) length through deadenylation and re-polyadenylation. Deadenylation appeared to be mediated by microRNAs (miRNAs), and transcripts with shorter poly(A) tails tend to be sequestered into ribonucleoproteins (RNPs) for translational repression and stabilization. In contrast, re-polyadenylation allows for translocation of the translationally repressed transcripts from RNPs to polysomes for translation. Overall, our data suggest that miRNA-dependent poly(A) length control represents a novel mechanism underlying uncoupled translation and transcription in haploid male germ cells.


1997 ◽  
Vol 17 (5) ◽  
pp. 2756-2763 ◽  
Author(s):  
B L Black ◽  
J Lu ◽  
E N Olson

Myocyte enhancer factor 2 (MEF2) proteins serve as important muscle transcription factors. In addition, MEF2 proteins have been shown to potentiate the activity of other cell-type-specific transcription factors found in muscle and brain tissue. While transcripts for MEF2 factors are widely expressed in a variety of cells and tissues, MEF2 proteins and binding activity are largely restricted to skeletal, smooth, and cardiac muscle and to brain. This disparity between MEF2 protein and mRNA expression suggests that translational control may play an important role in regulating MEF2 expression. In an effort to identify sequences within the MEF2A message which control translation, we isolated the mouse MEF2A 3' untranslated region (UTR) and fused it to the chloramphenicol acetyltransferase (CAT) reporter gene. Here, we show by CAT assay that the MEF2A 3' UTR dramatically inhibits CAT gene expression in vivo and that this inhibition is due to an internal region within the highly conserved 3' UTR. RNase protection analyses demonstrated that the steady-state level of CAT mRNA produced in vivo was not affected by fusion of the MEF2A 3' UTR, indicating that the inhibition of CAT activity resulted from translational repression. Furthermore, fusion of the MEF2A 3' UTR to CAT inhibited translation in vitro in rabbit reticulocyte lysates. We also show that the translational repression mediated by the 3' UTR of MEF2A is regulated during muscle cell differentiation. As muscle cells in culture differentiate, the translational inhibition caused by the MEF2A 3' UTR is relaxed. These results demonstrate that the MEF2A 3' UTR functions as a cis-acting translational repressor both in vitro and in vivo and suggest that this repression may contribute to the tissue-restricted expression and binding activity of MEF2A.


2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.


Oncogenesis ◽  
2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Xin Huang ◽  
Yichao Hou ◽  
Xiaoling Weng ◽  
Wenjing Pang ◽  
Lidan Hou ◽  
...  

AbstractExploring novel anticancer drugs to optimize the efficacy may provide a benefit for the treatment of colorectal cancer (CRC). Disulfiram (DSF), as an antialcoholism drug, is metabolized into diethyldithiocarbamate-copper complex (CuET) in vivo, which has been reported to exert the anticancer effects on various tumors in preclinical studies. However, little is known about whether CuET plays an anti-cancer role in CRC. In this study, we found that CuET had a marked effect on suppressing CRC progression both in vitro and in vivo by reducing glucose metabolism. Mechanistically, using RNA-seq analysis, we identified ALDH1A3 as a target gene of CuET, which promoted cell viability and the capacity of clonal formation and inhibited apoptosis in CRC cells. MicroRNA (miR)-16-5p and 15b-5p were shown to synergistically regulate ALDH1A3, which was negatively correlated with both of them and inversely correlated with the survival of CRC patients. Notably, using co-immunoprecipitation followed with mass spectrometry assays, we identified PKM2 as a direct downstream effector of ALDH1A3 that stabilized PKM2 by reducing ubiquitination. Taken together, we disclose that CuET treatment plays an active role in inhibiting CRC progression via miR-16-5p and 15b-5p/ALDH1A3/PKM2 axis–mediated aerobic glycolysis pathway.


2000 ◽  
Vol 74 (5) ◽  
pp. 1044-1046 ◽  
Author(s):  
Jan Tesarik ◽  
Natalio Cruz-Navarro ◽  
Eduardo Moreno ◽  
Maria Teresa Cañete ◽  
Carmen Mendoza
Keyword(s):  

2021 ◽  
Vol 95 (3) ◽  
pp. 1103-1116
Author(s):  
Francesco Marchetti ◽  
Gu Zhou ◽  
Danielle LeBlanc ◽  
Paul A. White ◽  
Andrew Williams ◽  
...  

AbstractThe Organisation for Economic Co-Operation and Development Test Guideline 488 (TG 488) uses transgenic rodent models to generate in vivo mutagenesis data for regulatory submission. The recommended design in TG 488, 28 consecutive daily exposures with tissue sampling three days later (28 + 3d), is optimized for rapidly proliferating tissues such as bone marrow (BM). A sampling time of 28 days (28 + 28d) is considered more appropriate for slowly proliferating tissues (e.g., liver) and male germ cells. We evaluated the impact of the sampling time on mutant frequencies (MF) in the BM of MutaMouse males exposed for 28 days to benzo[a]pyrene (BaP), procarbazine (PRC), isopropyl methanesulfonate (iPMS), or triethylenemelamine (TEM) in dose–response studies. BM samples were collected + 3d, + 28d, + 42d or + 70d post exposure and MF quantified using the lacZ assay. All chemicals significantly increased MF with maximum fold increases at 28 + 3d of 162.9, 6.6, 4.7 and 2.8 for BaP, PRC, iPMS and TEM, respectively. MF were relatively stable over the time period investigated, although they were significantly increased only at 28 + 3d and 28 + 28d for TEM. Benchmark dose (BMD) modelling generated overlapping BMD confidence intervals among the four sampling times for each chemical. These results demonstrate that the sampling time does not affect the detection of mutations for strong mutagens. However, for mutagens that produce small increases in MF, sampling times greater than 28 days may produce false-negative results. Thus, the 28 + 28d protocol represents a unifying protocol for simultaneously assessing mutations in rapidly and slowly proliferating somatic tissues and male germ cells.


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