Spanish scientists create extra-long-lived mice

piggy submitted, created time 1 month 3 weeks (www.enews20.com)

Spanish scientists have created "super-mice" that are cancer-resistant and live up to forty percent longer, media reported Friday.

The mice were subjected to genetic engineering by researchers from the cancer research centre CNIO and Valencia University.

The key to the experiment was an enzyme called telomerase, which lengthens chromosome ends known as telomeres.

Telomerase allows cells to keep dividing and is believed to increase longevity, but it also heightens the risk of cancer

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Mutations in the telomerase component NHP2 cause the premature aging syndrome dyskeratosis congenita

sea-maid submitted, created time 6 months 3 weeks (www.pnas.org)

Dyskeratosis congenita is a premature aging syndrome characterized by muco-cutaneous features and a range of other abnormalities, including early greying, dental loss, osteoporosis, and malignancy.

In this study, the author describe the analysis of two other proteins, NHP2 and GAR1, that together with dyskerin and NOP10 are key components of telomerase and small nucleolar ribonucleoprotein (snoRNP) complexes.

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Scientist of the Year Notable: Elizabeth Blackburn

Structure of the RNA-Binding Domain of Telomerase: Implications for RNA Recognition and Binding

salut8 submitted, created time 1 year 1 month (www.structure.org)

“Telomerase, a ribonucleoprotein complex, replicates the linear ends of eukaryotic chromosomes, thus taking care of the ‘end of replication problem’. TERT contains an essential and universally conserved domain (TRBD) that makes extensive contacts with the RNA (TER) component of the holoenzyme, and this interaction is thought to facilitate TERT/TER assembly and repeat-addition processivity. Here, Susan et al. present a high-resolution structure of TRBD from Tetrahymena thermophila. The nearly all-helical structure comprises a nucleic acid-binding fold suitable for TER binding

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Physiologically Achievable Concentrations of Genistein Enhance Telomerase Activity in Prostate Cancer Cells via the Activation of STAT3

jiangyun submitted, created time 1 year 4 months (carcin.oxfordjournals.org)

Although it is generally known that the phytoestrogen, genistein, has telomerase-repressing and anti-proliferative effects on various cancer cells at pharmacological concentrations, we report here that physiologically achievable concentrations of genistein enhance telomerase activity, the proliferation of human prostate cancer cells, and tumor growth in the Transgenic Adenocarcinoma Mouse Prostate (TRAMP) model.

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Evidence That a RecQ Helicase Slows Senescence by Resolving Recombining Telomeres

addict submitted, created time 1 year 7 months (biology.plosjournals.org)

"The RecQ family of DNA helicases process DNA recombination intermediates and also help ensure telomere integrity, but the relationship between these activities is poorly understood. Family members include yeast Sgs1p and human WRN and BLM, which are deficient in the Werner premature aging syndrome and the Bloom cancer predisposition syndrome, respectively. We have found that the telomeres of yeast cells lacking both telomerase and Sgs1p accumulate structures that resemble recombination intermediates."

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Telomere length of cord blood-derived CD34+ progenitors predicts erythroid proliferative potential

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

"Excessive telomere shortening has been demonstrated in inherited and acquired blood disorders, including aplastic anemia and myelodysplastic syndromes. It is possible that replicative exhaustion, owing to critical telomere shortening in hematopoietic progenitor cells (HPCs), contributes to the development of cytopenias in these disorders. "

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Protein Composition of Catalytically Active Human Telomerase from Immortal Cells

deirdre submitted, created time 1 year 9 months (www.sciencemag.org)

Telomerase is a ribonucleoprotein enzyme complex that adds 5'-TTAGGG-3' repeats onto the ends of human chromosomes, providing a telomere maintenance mechanism for ~90% of human cancers. We have purified human telomerase ~108-fold, with the final elution dependent on the enzyme's ability to catalyze nucleotide addition onto a DNA oligonucleotide of telomeric sequence, thereby providing specificity for catalytically active telomerase

1 comment | Blog It | Email It | Keywords: Telomerase ribonucleoprotein enzyme complex