Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0276640 (TEM)
 20,729 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously described a strategy for detecting protein protein interactions based on protein interaction assisted folding of rationally designed fragments of enzymes. We call this strategy the protein fragment complementation assay (PCA). Here we describe PCAs based on the enzyme TEM-1 beta-lactamase (EC: 3.5.2.6), which include simple colorimetric in vitro assays using the cephalosporin nitrocefin and assays in intact cells using the fluorescent substrate CCF2/AM (ref. 6). Constitutive protein protein interactions of the GCN4 leucine zippers and of apoptotic proteins Bcl2 and Bad, and the homodimerization of Smad3, were tested in an in vitro assay using cell lysates. With the same in vitro assay, we also demonstrate interactions of protein kinase PKB with substrate Bad. The in vitro assay is facile and amenable to high-throughput modes of screening with signal-to-background ratios in the range of 10:1 to 250:1, which is superior to other PCAs developed to date. Furthermore, we show that the in vitro assay can be used for quantitative analysis of a small molecule induced protein interaction, the rapamycin-induced interaction of FKBP and yeast FRB (the FKBP-rapamycin binding domain of TOR (target of rapamycin)). The assay reproduces the known dissociation constant and number of sites for this interaction. The combination of in vitro colorimetric and in vivo fluorescence assays of beta-lactamase in mammalian cells suggests a wide variety of sensitive and high-throughput large-scale applications, including in vitro protein array analysis of protein protein or enzyme protein interactions and in vivo applications such as clonal selection for cells expressing interacting protein partners.
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PMID:Beta-lactamase protein fragment complementation assays as in vivo and in vitro sensors of protein protein interactions. 1204 68

Cystic echinococcosis (CE) is a worldwide zoonosis caused by the Echinococcus granulosus larval stage. The currently available therapy for this disease is based on benzimidazoles, which are rarely curative and cause several adverse effects. Therefore, new treatment options are needed. Octreotide (Oct) is a somatostatin analogue which exhibits anti-proliferative and anti-secretory effects over several cancer cell lines expressing somatostatin receptors. Here, we assessed the in vitro pharmacological effect of Oct against the E. granulosus larval stage. The drug caused a significant dose-dependent decrease in the viability of both protoscoleces and metacestodes. SEM and TEM analysis showed ultrastructural damage in both larval forms under drug treatment. Based on this, we investigated the possible presence of an Oct binding receptor in the parasite. The putative somatostatin/allatostatin-like receptor (Eg-s/ast) conserves the characteristic topology and signature sequences of the prototype somatostatin receptor common to vertebrates and is expressed in both metacestodes and protoscoleces. Moreover, Oct treated-parasites showed the presence of autophagic structures and a significant increase in transcriptional expression of autophagy key genes such as Eg-atg6, Eg-atg8, Eg-atg12 and Eg-atg16. In addition, by in toto immunolocalization assays, an increase in the punctate pattern and Eg-Atg8 protein expression was detected in Oct-treated metacestodes. Subsequently, the combination of Oct and Met had an additive effect on the viability of both larval forms. Our results provide additional evidence for the participation of PI3K/AKT/TOR/autophagy pathway in the Echinococcus survival and suggest the concomitant use of these drugs as potential therapeutic agents in treating of CE.
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PMID:In vitro anti-echinococcal activity of octreotide: Additive effect of metformin linked to autophagy. 3187 Jul 10