Articles to be published in the May 4, 2007 issue of the Journal of Biological Chemistry (Vol. 282, No. 18)
Cholesterol Metabolism Without Oxygen
This article was featured as a “Paper of the Week” by the Journal of Biological Chemistry’s Editors, meaning that it belongs to the top one percent of papers reviewed in significance and overall importance.
Researchers report the first details of how cholesterol is metabolized without oxygen.
Cholesterol, a precursor to steroid hormones and a constituent of cell membranes, is usually broken down inside an organism in the presence of oxygen. The chemical reactions involved are well-known and have been used in industry to manufacture synthetic sexual hormones and dietary supplements. Cholesterol can also be broken down without oxygen, but very little is known about the chemical mechanisms at work.
Georg Fuchs and colleagues report the first study of these mechanisms. They used a bacterium called Sterolibacterium denitrificans and carefully looked at how cholesterol was broken down in this organism. The results, which revealed new compounds not previously seen in reactions involving oxygen, could be used to produce new pharmaceuticals for cholesterol-related diseases.
Article: “Initial steps in the anoxic metabolism of cholesterol by the denitrifying Sterolibacterium denitrificans” by Yin-Ru Chiang, Wael Ismail, Michael Muller, and Georg Fuchs
MEDIA CONTACT: Georg Fuchs, Mikrobiologie, Fakultat fur Biologie, Universitat Freiburg, Germany; tel: +49-7612032649; e-mail: firstname.lastname@example.org
Compound Effective against Blood Cancer Reveals Its Secrets
Scientists have revealed the mechanisms by which a natural compound destroys blood cancer cells.
Cyanidin, a chemical widely available in fruits, vegetables, and red wine, is known for its anticancer properties, but the details of how it works at the cellular level have been unclear – until now.
Xiao-Ming Yin and colleagues studied the effects of cyanidin on cultured cells from leukemia and lymphoma patients. They discovered that cyanidin increased the levels of molecules well-known for killing cells. These molecules, called reactive oxygen species, destroyed the cancer cells while sparing the surrounding healthy blood cells. These results could be used to develop new anticancer drugs, the scientists concluded.
Article: “Cyanidin-3-Rutinoside, a Natural Polyphenol Antioxidant, Selectively Kills Leukemic Cells by Induction of Oxidative Stress” by Rentian Feng, Hong-Min Ni, Shiow Y. Wang, Irina L. Tourkova, Michael R. Shulin, Hisashi Harada, and Xiao-Ming Yin
MEDIA CONTACT: Xiao-Ming Yin, Department of Pathology, University of Pittsburgh School of Medicine, Penn.; tel: 412-648-8436; e-mail: email@example.com
Fighting Bacteria by Preventing Them from Talking to Each Other
Researchers report the detailed structure of a key protein that helps bacteria talk to each other. The new finding could help devise new drugs targeting this protein.
Many bacteria communicate by sending molecules to each other. Such communication, called quorum sensing, helps them grow within a host without harming it, until they reach a certain concentration and become more aggressive. Of the many bacteria known to communicate by quorum sensing, Pseudomonas aeroginosa is the most studied because it causes death in the majority of cystic fibrosis sufferers and in AIDS patients, burn victims, and cancer patients.
Matthew Bottomley and colleagues described the chemical structure of the uppermost protein in the hierarchy of quorum sensing molecules. This protein, called LasR, activates other proteins that make the chemicals the bacteria use to communicate. The new result could help design new drugs against P. aeroginosa that inhibit LasR.
Article: “Molecular Insights into Quorum Sensing in the Human Pathogen Pseudomonas aeruginosa from the Structure of the Virulence Regulator LasR Bound to its Autoinducer” by Matthew J. Bottomley, Ester Muraglia, Renzo Bazzo & Andrea Carfì
MEDIA CONTACT: Matthew J. Bottomley, Istituto di Ricerche di Biologia Molecolare P.Angeletti, Pomezia (Rome), Italy; tel: +39-06-91093-502; e-mail: firstname.lastname@example.org
New Insight into HIV Infection
Scientists provide new information about how HIV, the virus that causes AIDS, enters the nucleus of an infected cell. This study could help devise a new way to fight AIDS.
When HIV infects a cell, it carries its DNA into the nucleus of the cell, then the viral DNA mixes with the cell’s DNA. The combined DNA produces proteins that make new viruses, which spread to neighboring cells. The mechanism by which HIV’s DNA enters the nucleus is not yet fully understood and may offer new ways to fight HIV.
Xiaojian Yao and colleagues studied how various cellular proteins help the virus enter the infected cell’s nucleus. They revealed new roles for these proteins that had not been fully established. The study also showed that by silencing genes that produce one of these proteins, HIV was three times less infectious than when the protein was present.
Article: “Interaction of Human Immunodeficiency Virus Type 1 Integrase with Cellular Nuclear Import Receptor Importin 7 and its Impact on Viral Replication” by Zhujun Ao, Guanyou Huang, Han Yao, Zaikun Xu, Meaghan Labine, Alan W. Cochrane, and Xiaojian Yao
MEDIA CONTACT: Xiaojian Yao, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, 508-730 William Avenue, Winnipeg, Manitoba, R3E 0W3 Canada; tel: 204-977-5677; e-mail: email@example.com
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