Soon, drugs to combat 'super bugs' Sep 9, 2007
Currently, three classes of bactericidal antibiotics are used to target different bacterial functions, inhibiting DNA replication, blocking protein-building; or halting construction of cell walls. Researchers found three classes more alike than earlier realised and this might be the downfall of the bug. (India Times, India -- Health/Science)
Antibiotics share killing mechanism Sep 7, 2007
One class inhibits DNA replication and repair, another inhibits protein synthesis, and the third prevents cell-wall turnover. "Prior thinking was that cell death arose principally from those interactions and that each [class] acted differently," said senior author of Boston University. (The Scientist)
Boston University biomedical engineers find chink in bacteria's armor Sep 7, 2007
Currently, three classes of bactericidal antibiotics are used to target different bacterial functions: inhibiting DNA replication; blocking protein-building; or halting construction of cell walls ... In studying bacterial response to a quinolone, an antibiotic that inhibits DNA replication, they noted a surprising change in genes responsible for energy production and iron uptake. (EurekAlert!)
A Nobel art form Sep 1, 2007
"In science, there is such a thing as the law of gravity, the laws of DNA replication, and so on, whereas in art, there are no laws." Instead of picking up the paintbrush of his youth, Guillemin chose the computers that had aided his scientific career as vehicles for artistic expression. In 1991, after creating several digital drawings, from impressionist landscapes to more abstract, interwoven streaks of color, on an ancient Macintosh 2CX computer, Guillemin took his work to in Santa Fe. (The Scientist)
DNA Replication Behavior In Complex Organisms May Foreshadow Leaps In Genomic Discoveries Aug 18, 2007
GIS Group Leader and the corresponding author of the publication, Dr Liu Jianhua, said, "Our evidence strongly supports the stochastic model for the regulation of DNA replication in high eukaryotes (organisms whose cells are organised into complex structures by internal membranes and a cytoskeleton) such as humans. We have shown that replication efficiency can be directly determined on a genomic scale. More significantly, our study provides for a novel methodology for the analysis of replication... (Science Daily)
NIEHS researchers identify enzyme critical in DNA replication Jul 6, 2007
According to Pursell, a researcher in the DNA Replication Fidelity Group at NIEHS and first author on the paper the studys findings advance the fundamental understanding of how the genomes of many higher organisms are replicated ... Participates in Leading-Strand DNA Replication. (EurekAlert!)
Pregnancy Nausea and Vomiting May Indicate Lower Risk Of Breast Cancer Jun 26, 2007
"Jaworowicz noted that the presence or absence of these pregnancy-related conditions may indicate a different course or extent of hormone-regulated breast tissue proliferation and differentiation during pregnancy, but also may indicate distinct hormonal profiles that persist following pregnancy.Although pregnancy conditions other than nausea and vomiting were not associated statistically with breast cancer risk, these were only preliminary findings, he added, based mainly upon whether women... (Science Daily)
Targeting key proteins of carcinogenesis Jun 23, 2007
This includes fundamental cellular programs such as protein degradation, DNA replication, signal transduction or protein trafficking. Up to now it was believed that the cooperation of three enzymes is needed to attach Ub to another protein: E1, E2 and E3. (EurekAlert!)
Carbon Metabolism And DNA Replication Tightly Linked, Study Finds May 18, 2007
Janni;re L, Canceill D, Suski C, Kanga S, Dalmais B, et al. (2007) Genetic Evidence for a Link Between Glycolysis and DNA Replication. PLoS ONE 2(5): e447. (Science Daily)
Unstable Leukemia Stem Cells May Predispose Patients To Drug Resistance May 9, 2007
"Although this study was not designed to identify mutations that would contribute to disease progression, our results suggest that these would also be found. These considerations highlight the importance of gaining further understanding of the control of DNA replication and repair in the leukemic stem cells from patients with chronic phase [chronic myeloid leukemia] in future efforts to devise therapies with curative potential," the authors write. In an accompanying editorial, Margret Rodrigues,... (Science Daily)
Deletion of the cruciform binding domain in CBP/14-3-3 displays reduced origin binding and initiation of DNA replication in budding yeast Apr 13, 2007
Initiation of eukaryotic DNA replication involves many protein-protein and protein-DNA interactions ... 14-3-3, a cruciform DNA binding protein, associates with yeast origins of replication and functions as an initiator of DNA replication, presumably through binding to cruciform DNA forming at yeast replicators. (BioMed Central)
Far-Out Physics Books Mar 24, 2007
Black Holes & Time Warps by Kip S. Thorne. Real physics is often weirder than science fiction. (Suite101.com)
My life as an advisor to TV and film Mar 17, 2007
Sometimes I am contacted by a screenwriter who has only a germ of an idea he wishes to flesh out, sometimes by a producer or director for edits on a script already in production, and sometimes by the production's Visual Effects Department asking how best to depict DNA replication by (CGI) on the screen. For an episode of I got a writing credit for a story on Munchausen syndrome (a patient feigning pheochromocytoma). (The Scientist)
Mutant Mouse Provides Insights Into Breast Cancer Dec 14, 2006
By discovering a mutant mouse that is highly susceptible to mammary tumors, Cornell researchers have found a novel potential link between genetic defects in DNA replication (copying) and breast cancer ... The arrows point to chromosomes with breaks or aberrations resulting from flawed DNA replication ... Mcm4 is essential for DNA replication and thus cell growth, according to Schimenti. (Science Daily)
Preliminary Results from Sunesis Pharmaceuticals' Phase 1 Trial of SNS-595 in Patients with Advanced Leukemias Demonstrate Promising Clinical Activity Dec 11, 2006
SNS-595 is a naphthyridine analog that selectively targets and kills proliferating cells during the DNA replication phase of the cell cycle. "SNS-595's activity among patients with advanced relapsed or refractory acute leukemias is encouraging as there is no standard treatment regimen for such patients, who generally have a very poor prognosis," said Jeffrey E. Lancet, M.D., Professor, Department of Hematologic Malignancies of the H. Lee Moffitt Cancer Center rch Institute and a principal... (PR Newswire)
Switching Bacteria Off May Be Possible with New Class of Antibiotic Dec 6, 2006
The majority of antibiotics thwart the bacterial cell by targeting either ribosomes to stop protein synthesis or the proteins involved in DNA replication. Some antibiotics work by interfering with the biosynthesis of cell walls, or with folate--a form of vitamin B integral to the maintenance of new cells. (Scientific American)
Cause Of Nerve Fiber Damage In Multiple Sclerosis Identified Oct 31, 2006
In addition to the energy-production function, GAPDH is involved with a number of genetic activities, such as RNA translocation, DNA replication and DNA repair. Other recent studies have shown that binding of inhibitors to GAPDH and TPI causes decreased ATP production in neurons, followed by progressive neuronal degeneration and death. (Science Daily)
Is that beer on your tie? Oct 21, 2006
"Take line DNA replication. It's so complex. The multiple mechanisms are just incredible. Far more beautiful than any photo I have taken.". Carlin Flora. (The Scientist)
New study shows how genetic repair mechanism helps seal DNA breaks Oct 20, 2006
"These results are exciting because they reveal for the first time how these proteins can dynamically assemble and change their shape to join DNA ends during DNA replication and repair," said a senior author of the paper John Tainer, who is a professor at Scripps Research, member of Scripps Research's Skaggs Institute for Chemical Biology, and co-principal investigator of the Structural Cell Biology of DNA Repair project in Berkeley Lab's Life Sciences Division. As the genetic material, DNA is... (EurekAlert!)
Tiny Genome May Reflect Organelle in the Making Oct 14, 2006
C. rudii is rich in genes for protein synthesis but lacks many genes for membrane synthesis, energy metabolism and DNA replication. Some of these genes may have been transferred to the host, which could be supplying its symbiont with essential enzymes, Moran notes. (Scientific American)
Tuning the body's defence to cancer Sep 7, 2006
Our cells contain a protein called p53, dubbed 'the guardian of the genome', which regulates the process of DNA replication. It also plays a crucial role in cancer: 50% of human tumours contain a mutation or a deletion in the gene that makes p53. (Nature News Service)
Researcher Studies Gene Families To Explore Diversity And Evolution Sep 6, 2006
"The growth of a gene family can occur through rare errors in DNA replication," Proulx said. "Sometimes in error, a single gene is duplicated on a chromosome, and the duplicated copy can emerge as a new functional gene. Although that gene may have a new function, it's not fundamentally different from the original gene.". (Science Daily)
Aviva Systems Biology Launches ChIP-GLAS Service for the Simultaneous Detection of 20,000 Human Promoters From a Single Sample Aug 9, 2006
ChIP-GLAS technology has many important applications that are useful for the understanding of transcription factor/DNA interactions: transcriptional regulation, DNA methylation, mRNA splicing, DNA damage repair, DNA replication, gene deletion and duplication, and many others. Based in San Diego, California, Aviva Systems Biology is dedicated to the development of reagents for transcription factor research including ChIP-GLAS promoter array systems and antibodies to over 2400 human and mouse... (PR Newswire)
Penn researchers determine structure of smallpox virus protein bound to DNA Aug 5, 2006
"The structure of the DNA complex has been long-awaited." DNA-modifying enzymes bind to specific sequences in the genetic code to aid in the many steps of DNA replication ... One of these enzymes is a topoisomerase, which is used by the virus to relieve the excessive twisting of DNA strands that normally occurs during DNA replication and transcription of the viral genes. (EurekAlert!)
Association Between Famine And Schizophrenia May Yield Clues About Inherited Diseases And Conditions Aug 3, 2006
"Folate has a major role in genetic processes -- gene transcription and regulation, DNA replication, and the repair of damaged genetic information," explained co-author Dr. Jack McClellan, an associate professor of psychiatry at the University of Washington and medical director of the Child Study and Treatment Center in Tacoma, Wash. "If folate is missing from a mother's diet, that could lead to genetic mutations in the developing fetus.". (Science Daily)
Prognostic significance of MCM2, Ki-67 and gelsolin in non-small cell lung cancer Aug 2, 2006
It plays critical roles in the initiation of DNA replication and in replication fork movement, and is intimately related to cell proliferation. Ki-67 is a proliferation antigen that is expressed during all but G0 phases of the cell cycle. (BioMed Central)
Computational model simulates AZT metabolism in mitochondria Jul 25, 2006
Drugs like AZT may interfere with DNA replication in the mitochondria, the energy factories of our cells, and can lead to potentially fatal side effects in patients undergoing HAART treatment ... When AZT reaches a cell, it is subject to some of the same metabolic modifications or phosphorylation events that are encountered by the four naturally occurring deoxynucleosides, the building blocks used to make DNA. However, modified AZT molecules lack a specific chemical group (a hydroxyl group) that... (EurekAlert!)
Molecular DNA Switch Found To Be The Same For All Life Jul 18, 2006
Researchers with the U.S. Department of Energy s Lawrence Berkeley National Laboratory and the University of California at Berkeley have shown that the core machinery for initiating DNA replication is the same for all three domains of life - Archaea, Bacteria and Eukarya ... In two papers that will be concurrently published in the August edition of the journal Nature Structural and Molecular Biology (now available on-line), the researchers report the identification of a helical substructure... (Science Daily)
Feeling Seasick? Jul 15, 2006
Part of a family of viruses called Calciviruses, its genetic information is coded with RNA, not DNA. RNA replication lacks the proofreading inherent in DNA replication, making it very error-prone. Every virus replicated will have one to ten mistakes in the genetic code. (FirstScience.com)
Australian Scientists Crack DNA Replication Mystery Jul 2, 2006
Posted: June 30, 2006. A team of scientists led by Professor Nick Dixon at the Research School of Chemistry at The Australian National University have cracked one of the great DNA mysteries. (Science Daily)
Infected for life: How the Herpes Simplex Virus Uses MicroRNA to Hide Out in Cells Jun 14, 2006
Posted: June 13, 2006. Researchers at the University of Pennsylvania School of Medicine have discovered part of the reason why cold sores, caused by a herpes virus, come back again and again. (Science Daily)
Infected for life Jun 13, 2006
Present treatments of HSV-1 rely on acyclovir-based drugs that target the viral polymerase and inhibit viral DNA replication during the acute infection. However, they do not target the latent infection, and thus cold sores return throughout the lifetime of the infected individual. (EurekAlert!)
DNA repair mapped, systems-wide May 20, 2006
Many cellular processes -- including DNA replication and repair, cell cycle control, metabolism, and stress responses -- form an integrated response to DNA damage, according to a in this week's Science ... At the core of the network lies a set of known DNA damage response genes, but surrounding these genes are interacting networks involved in DNA replication and repair, cell cycle arrest, stress responses, and metabolic pathways. (The Scientist)
Carroll County joins a move to put physics first May 9, 2006
Physics-first proponents maintain that the study of biology has become increasingly complicated, in part because of advanced topics such as DNA replication that must be taught. They say that students do better if they have first mastered such concepts as the structure of atoms and molecules, which are taught in physics and chemistry. (SunSpot.net)
Environmental Triggers May Promote Human Genetic Variation May 2, 2006
Genome Research, scientists from Kyushu University report how environmentally damaged DNA may contribute to human genetic diversity. They describe the co-occurrence of an aberrant nucleobase, called 8-oxoguanine (8-oxoG), with genomic regions enriched in meiotic recombination "hotspots" and single nucleotide polymorphisms (SNPs). (Science Daily)
Evolution said faster in the tropics May 2, 2006
Higher metabolism also speeds up DNA replication, which is just another chemical reaction, and this can increase the number of copying mistakes that can occur. Together, damage to DNA by free radicals and replication mistakes could result in mutations that, over time and through pressures, can form new species. (MSNBC -- Technology)
Evolution Occurs Faster at the Equator, Study Says May 2, 2006
Warmer temperatures speed up metabolism by allowing chemical reactions to occur at a faster rate, but this increased efficiency comes at a price: it produces higher quantities of charged atoms or molecules called "free radicals," which can damage proteins including DNA. Higher metabolism also speeds up DNA replication, which is just another chemical reaction, and this can increase the number of copying mistakes that can occur. Together, damage to DNA by free radicals and replication mistakes... (Newsmax)
Environmental DNA Damage May Drive Human Mutation May 1, 2006
For guanine, or G, its oxidized version is called 8-oxoG. When lurking in the area during DNA replication, it bonds with adenine and causes the latter to pair with thymine rather than with its correct partner, unoxidized guanine. This is a permanent change, or mutation. (Scientific American)
Enzyme Crystal Structure Reveals 'Unexpected' Genome Repair Functions Apr 8, 2006
(October 19, 1999) -- Harvard researchers have created the first atomic-resolution image of a donut-shaped enzyme, or helicase, that unwinds the DNA double helix to expose its genetic letters for DNA replication. Michael. (Science Daily)
How do antibiotics kill bacterial cells but not human cells? Mar 13, 2006
Indeed, modern antibiotics act either on processes that are unique to bacteria--such as the synthesis of cell walls or folic acid--or on bacterium-specific targets within processes that are common to both bacterium and human cells, including protein or DNA replication ... Similarly, DNA replication must occur in both bacteria and human cells ... This enzyme relaxes tightly wound chromosomal DNA, thereby allowing DNA replication to proceed. (Scientific American)
Common Enzyme Is A Key Player In DNA Repair Jan 18, 2006
(September 30, 2005) -- Since the discovery of the structure of DNA, the paradigm for DNA replication has stated that the DNA itself codes for replication ... A faulty nucleotide the basic constituent of DNA can stall the temperamental DNA replication machinery as it unwinds and copies the genome in dividing cells ... They cannot actually repair a damaged strand of DNA, but they can smooth over the problem by inserting a nucleotide opposite the damaged partner, so the DNA replication machinery... (Science Daily)
