Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.1.25 (triphosphatase)
 1,529 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mammalian target of rapamycin, mTOR, is a protein Ser-Thr kinase that functions as a central element in a signaling pathway involved in the control of cell growth and proliferation. The activity of mTOR is controlled not only by amino acids, but also by hormones and growth factors that activate the protein kinase Akt. The signaling pathway downstream of Akt leading to mTOR involves the protein products of the genes mutated in tuberous sclerosis, TSC1 and TSC2, and the small guanosine triphosphatase, Rheb. In cells, mTOR is found in a complex with two other proteins, raptor and mLST8. In this review, we describe recent progress in understanding the control of the mTOR signaling pathway and the role of mTOR-interacting proteins.
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PMID:TOR signaling. 1466 32

This review is focused on pathways and mechanisms that might provide molecular links between the pathogenesis of renal and pulmonary disease in tuberous sclerosis complex and the pathogenesis of the neurologic manifestations of tuberous sclerosis complex. Tuberous sclerosis complex is an autosomal dominant disorder in which the manifestations can include seizures; mental retardation; autism; benign tumors of the brain, retina, skin, and kidneys; and pulmonary lymphangiomyomatosis. Lymphangiomyomatosis is a life-threatening lung disease affecting almost exclusively young women. Genetic data have demonstrated that the cells giving rise to renal angiomyolipomas, the most frequent tumor type in patients with tuberous sclerosis complex, exhibit differentiation plasticity. Genetic studies have also shown that the benign smooth muscle cells of angiomyolipomas and pulmonary lymphangiomyomatosis have the ability to migrate or metastasize to other organs. These findings indicate that hamartin and tuberin play functional roles in the regulation of cell migration and differentiation. The biochemical pathways responsible for these effects are not yet fully understood but might involve dysregulation of the small guanosine triphosphatase Rho. Similar pathways might contribute to aberrant neuronal differentiation and migration in tuberous sclerosis complex.
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PMID:Aberrant cellular differentiation and migration in renal and pulmonary tuberous sclerosis complex. 1556 18

Tuberous sclerosis complex 2 (TSC2), whose gene is frequently mutated in tuberous sclerosis, increases the guanosine triphosphatase (GTPase) activity of the small heterotrimeric GTP-binding protein (G protein) Rheb, thus resulting in the decreased activity of the mammalian target of rapamycin (mTOR), the master regulator of cell growth. Here, we describe the development of a nuclear magnetic resonance (NMR)-based, quantitative, real-time assay to explore the molecular mechanism of the intrinsic and TSC2-catalyzed GTPase activity of Rheb. We confirmed that TSC2 accelerated GTP hydrolysis by Rheb 50-fold through an "asparagine-thumb" mechanism to substitute for the nonfunctional "catalytic" glutamine of Rheb and we determined that catalysis was enthalpy driven. Most, but not all, of the disease-associated GTPase-activating protein (GAP) domain mutants of TSC2 that we examined affected its enzymatic activity. This method can now be applied to study the function and regulation of other GTPases.
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PMID:Characterization of the intrinsic and TSC2-GAP-regulated GTPase activity of Rheb by real-time NMR. 1917 17