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Sweet tooth gene
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News & Comment
in a silicon dioxide matrix, change colour from blue through to red when subjected to chemical, thermal or mechanical ‘stress’. Networks of the conjugated polydiactylenes are formed within nanoscopic channels in the matrix upon UV irradiation, and heating or chemically treating the composites causes subtle but predictable changes in the colour of the polymer. The UNM team envisage applications of the composites as ‘smart’ chemical- and temperature-sensitive analysers. MJD
Biocompatible all over A team of Russian chemists has developed a method for producing biocompatible implants of almost any design and material, reports ChemWeb.com (4 May). Based at the Mendeleev University of Chemical Technology, (Moscow, Russia) Alexander Korigodski and colleagues have found that treating materials such as Teflon or polycarbonate with a novel polyamine mixture which is then dried, leaves a hydrophilic, biocompatible coating on the entire surface of the material, whatever its shape and design. MJD
TRENDS in Biotechnology Vol.19 No.7 July 2001
Sweet tooth gene
Possible protein link to ageing and cancer
Two groups of researchers have independently reported the discovery of a candidate ‘sweetness’ gene (Nature Neuroscience, May, Nature Genetics, May). Using strains of mice that have lost the ability to taste sugars and sweeteners, the teams at Harvard University (Cambridge, MA, USA) and Mount Sinai School of Medicine (New York, NY, USA) found that a gene expressed in the tastebuds, T1r3, is absent in these mice, who do not have the receptors capable of binding and recognizing sugars. MJD
Biology three billion years ago
One-way traffic A new one-way microvalve has been developed at the University of WisconsinMadison, that could be used in microfluidic devices. Reporting in Applied Physics Letters (23 April), David Beebe and coworkers describe how they use a pHsensitive hydrogel, anchored to a V-shaped support, as a valve that opens and closes in response to changes in pH. In slightly alkaline conditions, the hydrogel swells and fluid flow through the V-shaped ‘gate’ is prevented. On moving to more acidic conditions, the hydrogel shrinks and fluid flow is permitted. MJD
Enzyme caught in a spin A team of researchers in Japan has presented remarkable photographs of the rotating ‘motor’ of the enzyme ATP synthase. The images (Nature, 19 April) show the enzyme rotating and releasing ATP molecules as it spins and were obtained by first attaching the enzyme to a gold micro-bead. The bead is large enough to be visualized using a microscope but small enough to allow the enzyme to spin. MJD
Celera Genomics’ database. The researchers found that almost half of the 1049 known Drosophila proteins in the SWISSPROT database were less than a 99% match with Celera’s data, some differing by several hundreds of amino acids. MJD
One popular hypothesis on how life was on Earth three billion years ago is that of the RNA world. In this ‘world’, the information describing biological systems is stored in RNA, a role nowadays mostly performed by DNA. RNA would also have acted as ribozymes having catalytic functions (nowadays mainly performed by proteins) necessary to replicate information-carrying molecules. In a paper by Wendy K. Johnston et al. (Science, 18 May) the ability of RNA to replicate other RNA molecules has been reported for the first time. The replicative feats of the ribozyme (up to 14 nucleotides) is humble in comparison to its proteinaceous counterparts. However, the accuracy of replication is approximately 95% and considering the ribozyme is an artificial construct, it is quite remarkable. DM
Drosophila database discrepancy Discrepancies between predicted and actual protein form and function have been reported by Samuel Karlin and coworkers in the 17 May issue of Nature, who used Drosophila sequence data deposited in
Researchers have found both a yeast and human protein that binds telomeres, the very ends of chromosomes, which contain repeating chains of DNA (Peter Baumann and Thomas R. Cech, Science, 11 May). It is thought that the function of telomeres is to act as a biological clock by signalling the cell to stop dividing after a certain point. The telomere end-binding protein is called Protection of Telomeres or POT-1. When the POT-1 gene was knocked out, the yeast could not maintain its normal linear chromosomes and the ends rapidly degraded. The finding could have implications that reach as far as the treatment of cancer (the POT-1 protein might have a role in regulating telomere replication), the human ageing process or the production of immortal cell-lines. DM
Better cancer model It has previously been argued that mouse cancer models do not accurately reflect the type of spontaneous events that are typical of many human cancers. A paper by Leisa Johnson et al. (Nature, 26 April) describes a mouse tumour model that spontaneously activates oncogenic alleles of the gene K-ras. These mice were highly predisposed to a range of tumour types, predominantly early onset lung cancer. There is an obvious potential for using the new mouse model to test both chemotherapies and chemopreventatives for lung cancer. DM
Bone marrow stem cells generate epithelium In the 4 May issue of Cell, Diane S. Krause et al., show that mouse bone marrow stem cells are capable of developing into the specialized epithelial cells that line the intestines, lung and skin. This study provides some of the first clear evidence that a transplanted bone marrow stem cell can not only reconstitute bone marrow, but might also have a role in healing these other tissues and organs. The work centres on five mice that were treated with high doses of
http://tibtech.trends.com 0167-7799/01/$ – see front matter © 2001 Elsevier Science Ltd. All rights reserved.
News & Comment
in a silicon dioxide matrix, change colour from blue through to red when subjected to chemical, thermal or mechanical ‘stress’. Networks of the conjugated polydiactylenes are formed within nanoscopic channels in the matrix upon UV irradiation, and heating or chemically treating the composites causes subtle but predictable changes in the colour of the polymer. The UNM team envisage applications of the composites as ‘smart’ chemical- and temperature-sensitive analysers. MJD
Biocompatible all over A team of Russian chemists has developed a method for producing biocompatible implants of almost any design and material, reports ChemWeb.com (4 May). Based at the Mendeleev University of Chemical Technology, (Moscow, Russia) Alexander Korigodski and colleagues have found that treating materials such as Teflon or polycarbonate with a novel polyamine mixture which is then dried, leaves a hydrophilic, biocompatible coating on the entire surface of the material, whatever its shape and design. MJD
TRENDS in Biotechnology Vol.19 No.7 July 2001
Sweet tooth gene
Possible protein link to ageing and cancer
Two groups of researchers have independently reported the discovery of a candidate ‘sweetness’ gene (Nature Neuroscience, May, Nature Genetics, May). Using strains of mice that have lost the ability to taste sugars and sweeteners, the teams at Harvard University (Cambridge, MA, USA) and Mount Sinai School of Medicine (New York, NY, USA) found that a gene expressed in the tastebuds, T1r3, is absent in these mice, who do not have the receptors capable of binding and recognizing sugars. MJD
Biology three billion years ago
One-way traffic A new one-way microvalve has been developed at the University of WisconsinMadison, that could be used in microfluidic devices. Reporting in Applied Physics Letters (23 April), David Beebe and coworkers describe how they use a pHsensitive hydrogel, anchored to a V-shaped support, as a valve that opens and closes in response to changes in pH. In slightly alkaline conditions, the hydrogel swells and fluid flow through the V-shaped ‘gate’ is prevented. On moving to more acidic conditions, the hydrogel shrinks and fluid flow is permitted. MJD
Enzyme caught in a spin A team of researchers in Japan has presented remarkable photographs of the rotating ‘motor’ of the enzyme ATP synthase. The images (Nature, 19 April) show the enzyme rotating and releasing ATP molecules as it spins and were obtained by first attaching the enzyme to a gold micro-bead. The bead is large enough to be visualized using a microscope but small enough to allow the enzyme to spin. MJD
Celera Genomics’ database. The researchers found that almost half of the 1049 known Drosophila proteins in the SWISSPROT database were less than a 99% match with Celera’s data, some differing by several hundreds of amino acids. MJD
One popular hypothesis on how life was on Earth three billion years ago is that of the RNA world. In this ‘world’, the information describing biological systems is stored in RNA, a role nowadays mostly performed by DNA. RNA would also have acted as ribozymes having catalytic functions (nowadays mainly performed by proteins) necessary to replicate information-carrying molecules. In a paper by Wendy K. Johnston et al. (Science, 18 May) the ability of RNA to replicate other RNA molecules has been reported for the first time. The replicative feats of the ribozyme (up to 14 nucleotides) is humble in comparison to its proteinaceous counterparts. However, the accuracy of replication is approximately 95% and considering the ribozyme is an artificial construct, it is quite remarkable. DM
Drosophila database discrepancy Discrepancies between predicted and actual protein form and function have been reported by Samuel Karlin and coworkers in the 17 May issue of Nature, who used Drosophila sequence data deposited in
Researchers have found both a yeast and human protein that binds telomeres, the very ends of chromosomes, which contain repeating chains of DNA (Peter Baumann and Thomas R. Cech, Science, 11 May). It is thought that the function of telomeres is to act as a biological clock by signalling the cell to stop dividing after a certain point. The telomere end-binding protein is called Protection of Telomeres or POT-1. When the POT-1 gene was knocked out, the yeast could not maintain its normal linear chromosomes and the ends rapidly degraded. The finding could have implications that reach as far as the treatment of cancer (the POT-1 protein might have a role in regulating telomere replication), the human ageing process or the production of immortal cell-lines. DM
Better cancer model It has previously been argued that mouse cancer models do not accurately reflect the type of spontaneous events that are typical of many human cancers. A paper by Leisa Johnson et al. (Nature, 26 April) describes a mouse tumour model that spontaneously activates oncogenic alleles of the gene K-ras. These mice were highly predisposed to a range of tumour types, predominantly early onset lung cancer. There is an obvious potential for using the new mouse model to test both chemotherapies and chemopreventatives for lung cancer. DM
Bone marrow stem cells generate epithelium In the 4 May issue of Cell, Diane S. Krause et al., show that mouse bone marrow stem cells are capable of developing into the specialized epithelial cells that line the intestines, lung and skin. This study provides some of the first clear evidence that a transplanted bone marrow stem cell can not only reconstitute bone marrow, but might also have a role in healing these other tissues and organs. The work centres on five mice that were treated with high doses of
http://tibtech.trends.com 0167-7799/01/$ – see front matter © 2001 Elsevier Science Ltd. All rights reserved.