Electrophoretic analysis of the major polypeptides of the human erythrocyte membrane.

http://dipbsf.uninsubria.it/monti/BFPN%202009/mTOR.pdf

Defining the Role of mTOR in Cancer

The process of translation requires substantial cellular resources. Cells have therefore evolved complex mechanisms to control overall protein synthesis as well as the translation of specific mRNAs that are crucial for cell growth and proliferation. At the heart of this process is the mammalian target of rapamycin (mTOR) signalling pathway, which senses and responds to nutrient availability, energy sufficiency, stress, hormones and mitogens to modulate protein synthesis. Here, we highlight recent findings on the regulators and effectors of mTOR and discuss specific cases that serve as paradigms for the different modes of mTOR regulation and its control of translation.

/pdf/molecular-mechanisms-of-mtor-mediated-translational-control-a9zhrpbeb4.pdf

Molecular mechanisms of mTOR-mediated translational control

Lang, Florian, Gillian L. Busch, Markus Ritter, Harald Volkl, Siegfried Waldegger, Erich Gulbins, and Dieter Haussinger. Functional Significance of Cell Volume Regulatory Mechanisms. Physiol. Rev. ...

Functional Significance of Cell Volume Regulatory Mechanisms

Regulation of glutathione synthesis

Vanadate is a potent (Na,K)-ATPase inhibitor found in ATP derived from muscle.

The regulation of amino acid transport in animal cells.

The multidrug resistance (mdr1) gene product, P-glycoprotein, is responsible for the ATP-dependent extrusion of a variety of compounds, including chemotherapeutic drugs, from cells. The data presented here show that cells with increased levels of the P-glycoprotein release ATP to the medium in proportion to the concentration of the protein in their plasma membrane. Furthermore, measurements of whole-cell and single-channel currents with patch-clamp electrodes indicate that the P-glycoprotein serves as an ATP-conducting channel in the plasma membrane. These findings suggest an unusual role for the P-glycoprotein.

https://www.pnas.org/content/pnas/90/1/312.full.pdf

The multidrug resistance (mdr1) gene product functions as an ATP channel.

THE enzyme (Na+, K+)ATPase exists in the plasma membrane of animal cells and maintains a high intracellular K+-to-Na+ ratio by coupling movement of these ions to the hydrolysis of ATP. This enzyme spans the plasma membrane1 and is asymmetrically positioned with the ATP hydrolysing site on the cytoplasmic side2. Cardiac glycosides inhibit the (Na+, K+)-ATPase by binding to the part of the enzyme facing the extracellular fluid3. Although there is considerable evidence that hormonal regulation of (Na+, K+)ATPase occurs in certain tissues4–8, no endogenous regulatory agents of the purified enzyme have been identified. Recently we discovered that vanadate (vanadium in the +5 oxidation state) inhibits purified (Na+, K+)ATPase from several tissues at concentrations of 10−7–10−8 M (refs 9,10). Vanadium has been established as a nutritional requirement in chickens and rats, and our estimates of the concentration of vanadium in muscle tissue (10−6–10−7 M) agree with concentrations measured in other tissues11. It is known that vanadate has properties similar to those of the phosphate ion12, and it therefore seemed likely that it might inhibit the enzyme by binding to the hydrolysis site which is on the cytoplasmic surface of the enzyme. We demonstrate here that vanadate is transported into the red cell and inhibits the (Na+, K +)ATPase from the cytoplasmic side.

Guido Guidotti

Papers

Vanadate is a potent (Na,K)-ATPase inhibitor found in ATP derived from muscle.

The regulation of amino acid transport in animal cells.

The multidrug resistance (mdr1) gene product functions as an ATP channel.

Vanadate inhibits the red cell (Na + , K + ) ATPase from the cytoplasmic side

Purification and cloning of a soluble ATP-diphosphohydrolase (apyrase) from potato tubers (Solanum tuberosum).