scholarly journals Cilia locally synthesize proteins to sustain their ultrastructure and functions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Hao ◽  
Yawen Chen ◽  
Xiumin Yan ◽  
Xueliang Zhu
Keyword(s):  
Ribosomal Proteins ◽  
Fragile X ◽  
Intraflagellar Transport ◽  
Ependymal Cells ◽  
Local Translation ◽  
Initiation Factors ◽  
Translation Initiation Factors ◽  
Tubulin Mrna ◽  
To Come ◽  
Protein Components

AbstractCilia are microtubule-based hair-like organelles propelling locomotion and extracellular liquid flow or sensing environmental stimuli. As cilia are diffusion barrier-gated subcellular compartments, their protein components are thought to come from the cell body through intraflagellar transport or diffusion. Here we show that cilia locally synthesize proteins to maintain their structure and functions. Multicilia of mouse ependymal cells are abundant in ribosomal proteins, translation initiation factors, and RNA, including 18 S rRNA and tubulin mRNA. The cilia actively generate nascent peptides, including those of tubulin. mRNA-binding protein Fmrp localizes in ciliary central lumen and appears to function in mRNA delivery into the cilia. Its depletion by RNAi impairs ciliary local translation and induces multicilia degeneration. Expression of exogenous Fmrp, but not an isoform tethered to mitochondria, rescues the degeneration defects. Therefore, local translation defects in cilia might contribute to the pathology of ciliopathies and other diseases such as Fragile X syndrome.

scholarly journals Identifying the Translatome of Mouse NEBD-Stage Oocytes via SSP-Profiling; A Novel Polysome Fractionation Method

2020 ◽  
Vol 21 (4) ◽  
pp. 1254 ◽  
Author(s):  
Tomas Masek ◽  
Edgar del Llano ◽  
Lenka Gahurova ◽  
Michal Kubelka ◽  
Andrej Susor ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Initiation Factors ◽  
Cytoskeleton Organization ◽  
Nuclear Envelope Breakdown ◽  
Maternal Mrna ◽  
Translation Initiation Factors ◽  
Polysome Profiling ◽  
Developmental Point

Meiotic maturation of oocyte relies on pre-synthesised maternal mRNA, the translation of which is highly coordinated in space and time. Here, we provide a detailed polysome profiling protocol that demonstrates a combination of the sucrose gradient ultracentrifugation in small SW55Ti tubes with the qRT-PCR-based quantification of 18S and 28S rRNAs in fractionated polysome profile. This newly optimised method, named Scarce Sample Polysome Profiling (SSP-profiling), is suitable for both scarce and conventional sample sizes and is compatible with downstream RNA-seq to identify polysome associated transcripts. Utilising SSP-profiling we have assayed the translatome of mouse oocytes at the onset of nuclear envelope breakdown (NEBD)—a developmental point, the study of which is important for furthering our understanding of the molecular mechanisms leading to oocyte aneuploidy. Our analyses identified 1847 transcripts with moderate to strong polysome occupancy, including abundantly represented mRNAs encoding mitochondrial and ribosomal proteins, proteasomal components, glycolytic and amino acids synthetic enzymes, proteins involved in cytoskeleton organization plus RNA-binding and translation initiation factors. In addition to transcripts encoding known players of meiotic progression, we also identified several mRNAs encoding proteins of unknown function. Polysome profiles generated using SSP-profiling were more than comparable to those developed using existing conventional approaches, being demonstrably superior in their resolution, reproducibility, versatility, speed of derivation and downstream protocol applicability.

scholarly journals Arginine in C9ORF72 Dipolypeptides Mediates Promiscuous Proteome Binding and Multiple Modes of Toxicity

2020 ◽  
Vol 19 (4) ◽  
pp. 640-654 ◽  
Author(s):  
Mona Radwan ◽  
Ching-Seng Ang ◽  
Angelique R. Ormsby ◽  
Dezerae Cox ◽  
James C. Daly ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Arginine Methylation ◽  
Translation Elongation ◽  
Initiation Factors ◽  
Translation Initiation Factors ◽  
Exit Tunnel ◽  
Endogenous Proteins ◽  
Ribosome Exit Tunnel ◽  
Dipeptide Repeat

C9ORF72-associated Motor Neuron Disease patients feature abnormal expression of 5 dipeptide repeat (DPR) polymers. Here we used quantitative proteomics in a mouse neuronal-like cell line (Neuro2a) to demonstrate that the Arg residues in the most toxic DPRS, PR and GR, leads to a promiscuous binding to the proteome compared with a relative sparse binding of the more inert AP and GA. Notable targets included ribosomal proteins, translation initiation factors and translation elongation factors. PR and GR comprising more than 10 repeats appeared to robustly stall on ribosomes during translation suggesting Arg-rich peptide domains can electrostatically jam the ribosome exit tunnel during synthesis. Poly-GR also recruited arginine methylases, induced hypomethylation of endogenous proteins, and induced a profound destabilization of the actin cytoskeleton. Our findings point to arginine in GR and PR polymers as multivalent toxins to translation as well as arginine methylation that may explain the dysfunction of biological processes including ribosome biogenesis, mRNA splicing and cytoskeleton assembly.

scholarly journals Blastocyst implantation failure relates to impaired translational machinery gene expression

Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Vicki Plaks ◽  
Eran Gershon ◽  
Amit Zeisel ◽  
Jasmine Jacob-Hirsch ◽  
Michal Neeman ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Ribosomal Proteins ◽  
Oocyte Quality ◽  
Confined Space ◽  
Translational Machinery ◽  
Initiation Factors ◽  
Translation Initiation Factors ◽  
Developmental Capacity ◽  
Blastocyst Implantation ◽  
And Biological Markers

Oocyte quality is a well-established determinant of embryonic fate. However, the molecular participants and biological markers that affect and may predict adequate embryonic development are largely elusive. Our aim was to identify the components of the oocyte molecular machinery that part take in the production of a healthy embryo. For this purpose, we used an animal model, generated by us previously, the oocytes of which do not express Cx43 (Cx43del/del). In these mice, oogenesis appears normal, fertilisation does occur, early embryonic development is successful but implantation fails. We used magnetic resonance imaging analysis combined with histological examination to characterise the embryonic developmental incompetence. Reciprocal embryo transfer confirmed that the blastocyst evolved from the Cx43del/deloocyte is responsible for the implantation disorder. In order to unveil the genes, the impaired expression of which brings about the development of defective embryos, we carried out a genomic screening of both the oocytes and the resulting blastocysts. This microarray analysis revealed a low expression ofEgr1,Rpl21andEif4a1in Cx43del/deloocytes and downregulation ofRpl15andEif4g2in the resulting blastocysts. We propose that global deficiencies in genes related to the expression of ribosomal proteins and translation initiation factors in apparently normal oocytes bring about accumulation of defects, which significantly compromise their developmental capacity. The blastocysts resulting from such oocytes, which grow within a confined space until implantation, may be unable to generate enough biological mass to allow their expansion. This information could be implicated to diagnosis and treatment of infertility, particularly to IVF.

scholarly journals Temperature-induced reorganisation of Schistocephalus solidus (Cestoda) proteome during the transition to the warm-blooded host

2021 ◽  
Author(s):  
Ekaterina Borvinskaya ◽  
Albina Kochneva ◽  
Polina Drozdova ◽  
Olga Balan ◽  
Victor Zgoda
Keyword(s):  
Ribosomal Proteins ◽  
Gasterosteus Aculeatus ◽  
Protein Composition ◽  
Short Term ◽  
Initiation Factors ◽  
Schistocephalus Solidus ◽  
Translation Initiation Factors ◽  
Short Term Experiment

The protein composition (proteome) of cestode Schistocephalus solidus was measured in an experiment simulating the transition of the parasite from a cold-blooded to a warm-blooded host. Infective S. solidus plerocercoids obtained from the three-spined stickleback Gasterosteus aculeatus were heated at 40 °C for 1 hour or cultured in vitro at 40 °C and 22 °C for 48 hours. In short-term experiment, the content of only one tegument protein was evidenced to decrease after heating. After long-term heating, which triggered parasite sexual maturation, an increase in the content of ribosomal proteins, translation initiation factors and enzymes of the amino acid biosynthesis pathway was observed. The synthesis of certain gene products for carbohydrate metabolism, including glycolysis/gluconeogenesis, was found to be regulated in parasite by temperature.

scholarly journals Dendritic BC1 RNA in translational control mechanisms

2005 ◽  
Vol 171 (5) ◽  
pp. 811-821 ◽  
Author(s):  
Huidong Wang ◽  
Anna Iacoangeli ◽  
Daisy Lin ◽  
Keith Williams ◽  
Robert B. Denman ◽  
...  
Keyword(s):  
Translation Initiation ◽  
Translational Control ◽  
Fragile X ◽  
Initiation Factor ◽  
Control Mechanisms ◽  
Initiation Factors ◽  
Translation Initiation Factors ◽  
Specific Effector

Translational control at the synapse is thought to be a key determinant of neuronal plasticity. How is such control implemented? We report that small untranslated BC1 RNA is a specific effector of translational control both in vitro and in vivo. BC1 RNA, expressed in neurons and germ cells, inhibits a rate-limiting step in the assembly of translation initiation complexes. A translational repression element is contained within the unique 3′ domain of BC1 RNA. Interactions of this domain with eukaryotic initiation factor 4A and poly(A) binding protein mediate repression, indicating that the 3′ BC1 domain targets a functional interaction between these factors. In contrast, interactions of BC1 RNA with the fragile X mental retardation protein could not be documented. Thus, BC1 RNA modulates translation-dependent processes in neurons and germs cells by directly interacting with translation initiation factors.

scholarly journals Ribosomal protein RACK1 facilitates efficient translation of poliovirus and other viral IRESs

2019 ◽  
Author(s):  
Ethan LaFontaine ◽  
Clare M. Miller ◽  
Natasha Permaul ◽  
Alex G. Johnson ◽  
Elliot T. Martin ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Host Cell ◽  
Translation Initiation ◽  
Ribosomal Proteins ◽  
Ribosomal Subunit ◽  
Luciferase Reporter ◽  
Entry Site ◽  
Translational Machinery ◽  
Initiation Factors ◽  
Translation Initiation Factors

AbstractViruses have evolved various strategies to ensure efficient translation using host cell ribosomes and translation factors. In addition to cleaving translation initiation factors required for host cell translation, poliovirus (PV) uses an internal ribosome entry site (IRES) to bypass the need for these translation initiation factors. Recent studies also suggest that viruses have evolved to exploit specific ribosomal proteins to enhance translation of their viral proteins. The ribosomal protein receptor for activated C kinase 1 (RACK1), a protein of the 40S ribosomal subunit, was previously shown to mediate translation of the 5′ cricket paralysis virus and hepatitis C virus IRESs. Here we found that while translation of a PV dual-luciferase reporter shows only a moderate dependence on RACK1, PV translation in the context of a viral infection is drastically reduced. We observed significantly reduced poliovirus plaque size and a delayed host cell translational shut-off suggesting that loss of RACK1 increases the length of the virus life cycle. Our findings further illustrate the involvement of the cellular translational machinery in PV infection and how viruses usurp the function of specific ribosomal proteins.

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