Search results for "recombinant"
showing 10 items of 1150 documents
Binding of PTEN to specific PDZ domains contributes to PTEN protein stability and phosphorylation by microtubule-associated serine/threonine kinases
2005
The tumor suppressor phosphatase PTEN is a key regulator of cell growth and apoptosis that interacts with PDZ domains from regulatory proteins, including MAGI-1/2/3, hDlg, and MAST205. Here we identified novel PTEN-binding PDZ domains within the MAST205-related proteins, syntrophin-associated serine/threonine kinase and MAST3, characterized the regions of PTEN involved in its interaction with distinctive PDZ domains, and analyzed the functional consequences on PTEN of PDZ domain binding. Using a panel of PTEN mutations, as well as PTEN chimeras containing distinct domains of the related protein TPTE, we found that the PTP and C2 domains of PTEN do not affect PDZ domain binding and that the …
Direct Activation of Bax by p53 Mediates Mitochondrial Membrane Permeabilization and Apoptosis
2004
The tumor suppressor p53 exerts its anti-neoplastic activity primarily through the induction of apoptosis. We found that cytosolic localization of endogenous wild-type or trans-activation–deficient p53 was necessary and sufficient for apoptosis. p53 directly activated the proapoptotic Bcl-2protein Bax in the absence of other proteins to permeabilize mitochondria and engage the apoptotic program. p53 also released both proapoptotic multidomain proteins and BH3-only proteins [Proapoptotic Bcl-2family proteins that share only the third Bcl-2homology domain (BH3)] that were sequestered by Bcl-xL. The transcription-independent activation of Bax by p53 occurred with similar kinetics and concentra…
LaXp180, a mammalian ActA-binding protein, identified with the yeast two-hybrid system, co-localizes with intracellular Listeria monocytogenes
2001
The Listeria monocytogenes surface protein ActA is an important virulence factor required for listerial intracellular movement by inducing actin polymerization. The only host cell protein known that directly interacts with ActA is the phosphoprotein VASP, which binds to the central proline-rich repeat region of ActA. To identify additional ActA-binding proteins, we applied the yeast two-hybrid system to search for mouse proteins that interact with ActA. A mouse cDNA library was screened for ActA-interacting proteins (AIPs) using ActA from strain L. monocytogenes EGD as bait. Three different AIPs were identified, one of which was identical to the human protein LaXp180 (also called CC1). Bind…
Induction of rapid and reversible cytokeratin filament network remodeling by inhibition of tyrosine phosphatases
2002
The cytokeratin filament network is intrinsically dynamic, continuously exchanging subunits over its entire surface, while conferring structural stability on epithelial cells. However, it is not known how cytokeratin filaments are remodeled in situations where the network is temporarily and spatially restricted. Using the tyrosine phosphatase inhibitor orthovanadate we observed rapid and reversible restructuring in living cells, which may provide the basis for such dynamics. By examining cells stably expressing fluorescent cytokeratin chimeras, we found that cytokeratin filaments were broken down and then formed into granular aggregates within a few minutes of orthovanadate addition. After …
Identificación y caracterización de proteínas de Strongyloides stercoralis de utilidad para el diagnóstico y control de la enfermedad mediante técnic…
2016
El nematodo Strongyloides stercoralis es el principal causante de la estrongiloidiasis humana. Debido a la capacidad del parásito de perpetuar un ciclo autoinfectivo la infección puede prolongarse durante años en el hospedador, dando lugar a una enfermedad crónica en personas inmunocompetentes, mientras que en condiciones de inmunosupresión puede desembocar en cuadros clínicos graves con elevadas tasas de mortalidad. La región de La Safor valenciana ha sido considerada foco endémico de este parásito desde hace más de un siglo, habiéndose diagnosticado cientos de casos desde entonces, suponiendo un problema sanitario en la región. La presente Tesis contribuye a la mejora en el conocimiento p…
Heparin-binding protein targeted to mitochondrial compartments protects endothelial cells from apoptosis.
1999
Neutrophil-borne heparin-binding protein (HBP) is a multifunctional protein involved in the progression of inflammation. HBP is stored in neutrophil granules and released upon stimulation of the cells in proximity to endothelial cells. HBP affects endothelial cells in multiple ways; however, the molecular and cellular mechanisms underlying the interaction of HBP with these cells are unknown. Affinity isolation and enzymatic degradation demonstrated that HBP released from human neutrophils binds to endothelial cell-surface proteoglycans, such as syndecans and glypican. Flow cytometry indicated that a significant fraction of proteoglycan-bound HBP is taken up by the endothelial cells, and we …
Organization and expression of the chum salmon insulin-like growth factor II gene
1997
AbstractIGF-II plays an important role in growth and development of vertebrates. In the present study, the characterization of the first fish IGF-II gene, chum salmon IGF-II, is described. The sIGF-II gene consists of four exons, spanning a region of 9 kbp, that encode the 214 aa IGF-II precursor. While the amino acid sequences of fully processed IGF-II of salmon and mammalian species are very similar, the prepro-peptide sequence deviates extensively in the signal- and E-peptide domains. The transcription initiation site of the sIGF-II gene was localized within a 30 nt region employing RT-PCR. Using sIGF-II promoter-luciferase constructs it was demonstrated that the sIGF-II gene has a relat…
Nitric oxide increases the decay of matrix metalloproteinase 9 mRNA by inhibiting the expression of mRNA-stabilizing factor HuR.
2003
Dysregulation of extracellular matrix turnover is an important feature of many inflammatory processes. Rat renal mesangial cells express high levels of matrix metalloproteinase 9 (MMP-9) in response to inflammatory cytokines such as interleukin-1 beta. We demonstrate that NO does strongly destabilize MMP-9 mRNA, since different luciferase reporter gene constructs containing the MMP-9 3' untranslated region (UTR) displayed significant reduced luciferase activity in response to the presence of NO. Moreover, by use of an in vitro degradation assay we found that the cytoplasmic fractions of NO-treated cells contained a higher capacity to degrade MMP-9 transcripts than those obtained from contro…
The Suppressor of fused Gene Encodes a Novel PEST Protein Involved in Drosophila Segment Polarity Establishment
1995
Abstract Suppressor of fused, Su(fu), was identified as a semi-dominant suppressor of the putative serine/threonine kinase encoded by the segment polarity gene fused in Drosophila melanogaster. The amorphic Su(fu) mutation is viable, shows a maternal effect and displays no phenotype by itself. Su(fu) mutations are often found associated to karmoisin (kar) mutations but two complementation groups can be clearly identified. By using a differential hybridization screening method, we have cloned the Su(fu) region and identified chromosomal rearrangements associated with Su(fu) mutations. Two classes of cDNAs with similar developmental patterns, including a maternal contribution, are detectable …
The 3'-UTR of the mRNA coding for the major protein kinase C substrate MARCKS contains a novel CU-rich element interacting with the mRNA stabilizing …
2003
The expression of the major protein kinase C substrate MARCKS (myristoylated alanine-rich C kinase substrate) is controlled by the stability of its mRNA. While the MARCKS mRNA is long living in quiescent fibroblasts (t1/2 = 14 h), its half-life time is drastically reduced (t1/2 = 2 h) in cells treated with phorbol esters to activate protein kinase C (PKC) or treated with growth factors. In a first step to study the underlying mechanism we identified both a cis-element on the MARCKS mRNA and the corresponding trans-acting factors. Fusing the complete 3'-UTR or specific regions of the 3'-UTR of the MARCKS gene to a luciferase reporter gene caused a drastic decrease in luciferase expression to…