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An intracellular protease of the crenarchaeon Sulfolobus solfataricus, which has sequence similarity to eukaryotic peptidases of the CD clan.
No full textAn intracellular protease of the crenarchaeon Sulfolobus solfataricus, which has sequence similarity to eukaryotic peptidases of the CD clan.
No full textThe Epithelial–Mesenchymal Transition at the Crossroads between Metabolism and Tumor Progression
Full text linkThe transition between epithelial and mesenchymal phenotype is emerging as a key determinant of tumor cell invasion and metastasis. It is a plastic process in which epithelial cells first acquire the ability to invade the extracellular matrix and migrate into the bloodstream via transdiffer-entiation into mesenchymal cells, a phenomenon known as epithelial–mesenchymal transition (EMT), and then reacquire the epithelial phenotype, the reverse process called mesenchymal–epithelial transition (MET), to colonize a new organ. During all metastatic stages, metabolic changes, which give cancer cells the ability to adapt to increased energy demand and to withstand a hostile new environment, are also important determinants of successful cancer progression. In this review, we describe the complex interaction between EMT and metabolism during tumor progression. First, we outline the main connections between the two processes, with particular emphasis on the role of cancer stem cells and LncRNAs. Then, we focus on some specific cancers, such as breast, lung, and thyroid cancer
The soluble ectodomain of Ret C634Y inhibits both the wild type and the constitutively active Ret.
No full textProneural-Mesenchymal Transition: Phenotypic Plasticity to Acquire Multitherapy Resistance in Glioblastoma
Full text linkGlioblastoma (GBM) is an extremely aggressive tumor of the central nervous system, with a prognosis of 12–15 months and just 3–5% of survival over 5 years. This is mainly because most patients suffer recurrence after treatment that currently consists in maximal resection followed by radio- and chemotherapy with temozolomide. The recurrent tumor shows a more aggressive behavior due to a phenotypic shift toward the mesenchymal subtype. Proneural-mesenchymal transition (PMT) may represent for GBM the equivalent of epithelial–mesenchymal transition associated with other aggressive cancers. In this review we frame this process in the high degree of phenotypic inter- and intra-tumor heterogeneity of GBM, which exists in different subtypes, each one characterized by further phenotypic variability in its stem-cell compartment. Under the selective pressure of different treatment agents PMT is induced. The mechanisms involved, as well as the significance of such event in the acquisition of a multitherapy resistance phenotype, are taken in consideration for future perspectives in new anti-GBM therapeutic options
The soluble ectodomain of Ret C634Y inhibits both the wild type and the constitutively active Ret.
No full textThe chaperonin from the archaeon Sulfolobus solfataricus promotes correct refolding and prevents thermal denaturation in vitro.
No full textWe have isolated a chaperonin from the hyperthermophilic archaeon Sulfolobus solfataricus based on its ability
to inhibit the spontaneous refolding 5a0t "C of dimeric S. solfataricus malic enzyme. The chaperonin, a 920-kDa
oligomer of 57-kDa subunits, displays a potassium-dependent ATPase activity with an optimum temperature at
80 "C. S. solfataricus chaperonin promotes correct refoldings of several guanidine hydrochloride-denatured enzymes
from thermophilic and mesophilic sources. At a molar ratio of chaperonin oligomer to single polypeptide
chain of 1: 1, S. solfataricus chaperonin completely inhibits spontaneous refoldings and suppresses aggregation
upon dilution of the denaturant; refoldings resume upon ATP hydrolysis, with yields of active molecules and rates
of folding notably higher than in spontaneous processes. S. solfataricus chaperonin prevents the irreversible inactivations at 90 "C of several thermophilic enzymes by the binding of the denaturation intermediate; the timecourses
of inactivations are unaffected and most activity is regained upon hydrolysis of ATP. S. solfataricus
chaperonin completely prevents the formation of aggregates during thermal inactivation of chicken egg white lysozyme
at 70 "C, without affecting the rate of activity loss; ATP hydrolysis results in the recovery of most lytic
activity. Tryptophan fluorescence measurements provide evidence that S. solfataricus chaperonin undergoes a dramatic
conformational rearrangement in the presence of ATP/Mg, and that the hydrolysis of ATP is not required
for the conformational change. The ATP/Mg-induced conformation of the chaperoisn in fully unable to bind the
protein substrates, probably due to disappearance or modification of the substrate binding sites. This is the first archaeal chaperonin whose involvement in protein folding has been demonstrated
The soluble ectodomain of Ret C634Y inhibits both the wild type and the constitutively active Ret.
No full textDBF (disulfide bond forming) from the hyperthermophilic archaebacterium Sulfolobus solfataricus behaves as a molecular chaperone.
No full textDBF enzyme from the hyperthermophilic archaebacterium Sulfolobus solfataricus greatly enhances the refolding at 30°C of denatured and reduced bovine pancreatic ribonuclease (Guagliardi et al., 1992). Here we show that DBF behaves like a molecular chaperone: it affects in an ATP-dependent manner the in vitro refolding at 50°C of two thermostable dehydrogenases, an alcohol dehydrogenase and a glutamate dehydrogenase from S. solfataricus. This paper also reports the complete amino acid sequence of DBF. The role of molecular chaperones from thermophilic microorganisms in applied biocatalysis is discussed
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