Navigation Links
A simple feedback resistor switch keeps latent HIV from awakening

ors found no experimental evidence for oligomerization of Tat; instead, both on and off forms appear to be monomers.

Other studies have shown that Tat is activated by the addition of an acetyl group--a functional group that is frequently added to (acetylation) or removed from (deacetylation) proteins to modify their properties--and that deacetylation inactivates Tat. Based on the known kinetics of both acetylation and deacetylation, the authors postulated that a resistor might exist in the Tat circuit. A simple mathematical model showed that the interconversion of the two forms, coupled with the known rate of breakdown of Tat, was sufficient to encode a resistor that explained Tat circuit shutoff and possibly the stability of HIV's latent state.

In the Tat resistor model, as in the cell, Tat deacetylation occurs at a much faster rate than acetylation. Deacetylated (inactive) Tat can take one of two paths--reconversion in to acetylated (active) Tat, or destruction of the protein by cellular machinery. When the appropriate conversion and destruction rates were fed into their model, activated Tat appeared briefly after a stray burst of transcription but quickly disappeared without breaking viral latency. This prediction of the model was then precisely replicated in cell culture experiments. An array of cell culture experiments perturbing the supposed Tat resistor was then performed. For example, inhibition of the deacetylating enzyme SirT1 induced Tat transcription activation in cells, further supporting the role of Tat acetylation in controlling viral dormancy. Finally, simulations under noisy conditions predicted that this simple resistor system was better able to resist environmental fluctuations than hypothetical oligomer-dependent switches, and cell-sorting experiments confirmed this prediction.

This simple switch, in which the deactivating reaction overpowers the activating rea ction under most circumstances, acts as a "feedback re
'"/>

Source:Public Library of Science


Page: 1 2 3

Related biology news :

1. Topical treatment shown to inhibit HIV and herpes simplex virus infection
2. Researchers trace evolution to relatively simple genetic changes
3. New technique multiplies life span in simple organisms
4. Jefferson biologist coaxing human embryonic stem cells to make dopamine with simpler, faster method
5. New evidence questions the simple link between prion proteins and madcow disease
6. Cheaper and simpler keyhole surgery
7. Microscopic scaffolding offers a simple solution to treating skin injuries
8. Scientists explore how complex organs develop from a simple bud
9. Scientists design simple dipstick test for cocaine, other drugs
10. The power of one: A simpler, cheaper method for cell fusion
11. Surgeons develop simpler way to cure atrial fibrillation
Post Your Comments:
*Name:
*Comment:
*Email:
TAG: simple feedback resistor switch keeps latent HIV from awakening

(Date:7/11/2014)... proteins that let nerve cells send out electrical signals, ... biological tactic that may offer a new way to ... environmentally responsible way. , Their findingthat naturally occurring ... harmless for a closely related onesuggests that insecticides can ... species like bees. A summary of the research, led ...
(Date:7/10/2014)... COLORADO SPRINGS, Colo. , June 27, 2014 ... announces that the National Institute of Standards and ... appointed 10 of its academic research and forensic ... Board (FSSB).  The Board is an element of ... These AAFS members are among the first appointments ...
(Date:7/10/2014)... 1, 2014 Smart technology emphasis grows ... and improved security: NXT-ID, Inc. (OTCBB: NXTD), eBay Inc. (NASDAQ: ... ), Apple Inc. (NASDAQ: AAPL ), Visa Inc. ... NXT-ID, Inc., (OTCQB: NXTD) a biometric authentication company focused ... the second series of 30 second spots on CNBC for ...
Breaking Biology News(10 mins):Potent spider toxin 'electrocutes' German, not American, cockroaches 2Potent spider toxin 'electrocutes' German, not American, cockroaches 3Ten Members of the American Academy of Forensic Sciences Appointed to Forensic Science Standards Board (FSSB) 2Ten Members of the American Academy of Forensic Sciences Appointed to Forensic Science Standards Board (FSSB) 3Advantages for Digital Wallets Eliminate Need to Carry Credit Cards - Large Scale CNBC Ad Campaign for Latest Smart Wallet to Commence July 7th 2Advantages for Digital Wallets Eliminate Need to Carry Credit Cards - Large Scale CNBC Ad Campaign for Latest Smart Wallet to Commence July 7th 3Advantages for Digital Wallets Eliminate Need to Carry Credit Cards - Large Scale CNBC Ad Campaign for Latest Smart Wallet to Commence July 7th 4Advantages for Digital Wallets Eliminate Need to Carry Credit Cards - Large Scale CNBC Ad Campaign for Latest Smart Wallet to Commence July 7th 5
... More than 20 million tons of plastic are placed in ... Missouri study suggest that some of the largely petroleum-based plastic ... from plants. Reducing the carbon footprint and the dependence on ... additional cash crop for farmers. "Making plastics from plants ...
... Institute of Standards and Technology (NIST) has developed ... an important quality assurance tool for measuring the ... dietary supplements. The new Standard Reference Material (SRM) ... with the Office of Dietary Supplements (ODS) at ...
... are two species of lice that infest humans: pubic lice, ... Pediculus humanus . A new article in BioMed Central,s ... for the separation of the two species. ... how he was struck by inspiration while pondering the question ...
Cached Biology News:'Green' plastics could help reduce carbon footprint 2New reference material can improve testing of multivitamin tablets 2
(Date:7/10/2014)... to the International Atomic Energy Agency (IAEA) the ... acquiring sufficient quantities of plutonium or highly enriched ... device. The IAEA also notes that most cases ... which can be challenging to detect with most ... appearing this week in the Journal of ...
(Date:7/10/2014)... June 17, 2014 Using microscopic polymer light ... gases, researchers at MIT,s Quantum Photonics Laboratory have ... in the parts-per-billion range. Optical sensors are ideal ... high signal-to-noise ratio, compact, lightweight nature, and immunity ... sensors had been developed before, the MIT team ...
(Date:7/10/2014)... Understanding the basis of psychiatric disorders has been extremely ... increase risk but are insufficient to cause disease. Now ... Cell Press journal Cell Stem Cell describe ... genetic risks interact with other risk factors or environmental ... Their research pinpoints a genetic variant that may predispose ...
(Date:7/10/2014)... that power our laptops and electric vehicles could store ... with the help of a sponge-like silicon material. ... graphite traditionally used in one of the battery,s electrodes, ... storage capacity of graphite. A paper describing the material,s ... in Nature Communications . , "Silicon has long ...
Breaking Biology Technology:Sensitive detection method may help impede illicit nuclear trafficking 2Swell new sensors 2New strategy could uncover genes at the root of psychiatric illnesses 2Silicon sponge improves lithium-ion battery performance 2Silicon sponge improves lithium-ion battery performance 3
... , , EMERYVILLE, Calif., ... today the publication of results from its study on the ... published in the International Journal of Cancer , describe ... effect induced by BN107 on estrogen receptor negative (ER-) breast ...
... , ... The Aesthetic Institute of New York and New Jersey, recently started using ... latest information in facial plastic surgery techniques, new products and beauty trends ... believe that using Twitter connects me to my patients on a more ...
... TSX symbol: SBS , CALGARY, Dec. 24 /PRNewswire-FirstCall/ - ... its progress on plant-produced Apo AI(Milano) in light of ... The Medicines Company, of Parsippany, New Jersey. , "The ... Apo AI(Milano) program is a strong endorsement of Apo ...
Cached Biology Technology:Bionovo Announces Publication Describing First Novel Dual mTOR Inhibitor, BN107, for the Treatment of Breast Cancer 2Bionovo Announces Publication Describing First Novel Dual mTOR Inhibitor, BN107, for the Treatment of Breast Cancer 3New York Plastic Surgeon Transforms His Practice Using Twitter Status Updates 2New York Plastic Surgeon Transforms His Practice Using Twitter Status Updates 3SemBioSys updates progress on Apo AI(Milano) 2SemBioSys updates progress on Apo AI(Milano) 3