Lost in translation

piggy submitted, created time 20 hours 8 minutes (www.eurekalert.org)

The enzyme machine that translates a cell's DNA code into the proteins of life is nothing if not an editorial perfectionist.

Johns Hopkins researchers, reporting this week in Nature, have discovered a new proofreading step during which the suite of translational tools called the ribosome recognizes errors, just after making them, and definitively responds by hitting its version of a delete button

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Oncogenesis: It's all about translation

sea-maid submitted, created time 4 weeks 1 day (www.nature.com)

The oncogene MYC regulates many cellular processes, making it difficult to pin down its precise function in driving tumor development. Maria Barna, David Ruggero and colleagues suggest that changes to cap-dependent and cap-independent translation during mitosis are pivotal.

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Translation factors promote the formation of two states of the closed-loop mRNP

kavin submitted, created time 7 months 2 weeks (www.ncbi.nlm.nih.gov)

In the paper, the authors use toeprinting and polysome profiling assays to delineate ribosome positioning at initiator AUG codons and ribosome-mRNA association, respectively, and find that two distinct stable (resistant to cap analogue) closed-loop structures are formed during initiation in yeast cell-free extracts. The integrity of both forms requires the mRNA cap and poly(A) tail, as well as eIF4E, eIF4G, Pab1 and eIF3, and is dependent on the length of both the mRNA and the poly(A) tail.

2 comments | Blog It | Email It | Keywords: Pab1 eIF3 eIF4G eIF4E mRNA AUG ribosomes polysomes translation mRNP closed-loop mRNP Translation factors

Position of eukaryotic initiation factor eIF5B on the 80S ribosome mapped by directed hydroxyl radical probing

addict submitted, created time 1 year 6 months (www.nature.com)

Eukaryotic translation initiation factor eIF5B is a ribosome-dependent GTPase that mediates displacement of initiation factors from the 40S ribosomal subunit in 48S initiation complexes and joining of 40S and 60S subunits. Here, we determined eIF5B's position on 80S ribosomes by directed hydroxyl radical cleavage

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UVC inhibits HIF-1alpha protein translation by a DNA damage- and topoisomerase I-independent pathway

sciencebaby submitted, created time 1 year 7 months (www.nature.com)

Hypoxia inducible factor 1 (HIF-1) is a key player in cancer progression and an attractive target for cancer therapy. Several small molecule inhibitors of HIF-1alpha also induce a DNA damage response. However, whether or not DNA damage is required for or associated with the inhibition of HIF-1alpha protein accumulation is poorly understood. In this report we investigated the effects of distinct DNA damaging conditions on the hypoxic induction of HIF-1alpha protein in cancer cell lines.

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Rhythmic control of AANAT translation by hnRNP Q in circadian melatonin production

badboy submitted, created time 1 year 9 months (www.genesdev.org)

"The circadian rhythm of pineal melatonin requires the nocturnal increment of serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase [AANAT]) protein. To date, only limited information is available in the critical issue of how AANAT protein expression is up-regulated exclusively at night regardless of its species-specific mRNA profiles."

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A novel checkpoint mechanism regulating the G1/S transition

athena submitted, created time 1 year 9 months (www.genesdev.org)

"Ultraviolet irradiation of fission yeast cells in G1 phase induced a delay in chromatin binding of replication initiation factors and, consistently, a transient delay in S-phase entry. The cell cycle delay was totally dependent on the Gcn2 kinase, a sensor of the nutritional status, and was accompanied by phosphorylation of the translation initiation factor eIF2 and by a general depression of translation. However, the G1-specific synthesis of factors required for DNA replication was not reduced by ultraviolet radiation

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Fragile X Mental Retardation Protein Induces Synapse Loss through Acute Postsynaptic Translational Regulation

alpha submitted, created time 1 year 9 months (www.jneurosci.org)

"Fragile X syndrome, as well as other forms of mental retardation and autism, is associated with altered dendritic spine number and structure. Fragile X syndrome is caused by loss-of-function mutations in Fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates protein synthesis in vivo."

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RIBOSOME DYNAMICS: Insights from Atomic Structure Modeling into Cryo-Electron Microscopy Maps

biscuits submitted, created time 1 year 11 months (arjournals.annualreviews.org)

Interpretation of cryo-EM reconstructions of the ribosome in quasi-atomic detail reveals a picture in which the ribosome uses RNA not only to catalyze chemical reactions, but also as a means for signal transduction over large distances.

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