Search results for "ubiquitin ligase"

Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation

2015

Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PI…

Ubiquitin ligase Rsp5p is involved in the gene expression changes during nutrient limitation inSaccharomyces cerevisiae

2009

Rsp5p is an essential ubiquitin ligase involved in many different cellular events, including amino acid transporters degradation, transcription initiation and mRNA export. It plays important role in both stress resistance and adaptation to the change of nutrients. We have found that ubiquitination machinery is necessary for the correct induction of the stress response SPI1 gene at the entry of the stationary phase. SPI1 is a gene whose expression is regulated by the nutritional status of the cell and whose deletion causes hypersensitivity to various stresses, such as heat shock, alkaline stress and oxidative stress. Its regulation is mastered by Rsp5p, as mutations in this gene lead to a lo…

Spatially restricted expression of strim, a novel TRIM-containing gene, in the oral ectoderm of the developing sea urchin embryo Paracentrotus lividu…

2010

The recent wealth of genomic data has confirmed that bilaterians as simple as nematodes and as complex as humans use the same basic toolkit of transcription factors and signaling molecules to process spatial and temporal information during development (1,2). Among these regulators, the TRIM/RBCC (Tripartite motif/RING-Bbox-Coiled Coil) family represents one of the largest classes of putative E3 ubiquitin ligases that play essential roles in cell cycle regulation and development (3). It consists of rapidly evolving genes, identified in eukaryotic organisms (4,5). In the sea urchin Paracentrotus lividus we have identified a locus containing two copies, probably originated from a duplication e…

Protein Kinase C-dependent Ubiquitination and Clathrin-mediated Endocytosis of the Cationic Amino Acid Transporter CAT-1*

2011

Cationic amino acid transporter 1 (CAT-1) is responsible for the bulk of the uptake of cationic amino acids in most mammalian cells. Activation of protein kinase C (PKC) leads to down-regulation of the cell surface CAT-1. To examine the mechanisms of PKC-induced down-regulation of CAT-1, a functional mutant of CAT-1 (CAT-1-HA-GFP) was generated in which a hemagglutinin antigen (HA) epitope tag was introduced into the second extracellular loop and GFP was attached to the carboxyl terminus. CAT-1-HA-GFP was stably expressed in porcine aorthic endothelial and human epithelial kidney (HEK) 293 cells. Using the HA antibody internalization assay we have demonstrated that PKC-dependent endocytosis…

Insulin-like growth factor 1 differentially regulates estrogen receptor-dependent transcription at estrogen response element and AP-1 sites in breast…

2007

Cross-talk between insulin-like growth factor 1 (IGF-1) and estrogen receptor alpha (ER) regulates gene expression in breast cancer cells, but the underlying mechanisms remain unclear. Here, we studied how 17-beta-estradiol (E2) and IGF-1 affect ER transcriptional machinery in MCF-7 cells. E2 treatment stimulated ER loading on the estrogen response element (ERE) in the pS2 promoter and on the AP-1 motif in the cyclin D1 promoter. On ERE, similar amounts of liganded ER were found at 1-24-h time points, whereas on AP-1, ER binding fluctuated over time. At 1 h, liganded ER was recruited to ERE together with histone acetyltransferases SRC-1 and p300, ubiquitin ligase E6-AP, histone methyltransf…

Alix protein is substrate of Ozz-E3 ligase and modulates actin remodeling in skeletal muscle

2012

Alix/AIP1 is a multifunctional adaptor protein that participates in basic cellular processes, including membrane trafficking and actin cytoskeleton assembly, by binding selectively to a variety of partner proteins. However, the mechanisms regulating Alix turnover, subcellular distribution, and function in muscle cells are unknown. We now report that Alix is expressed in skeletal muscle throughout myogenic differentiation. In myotubes, a specific pool of Alix colocalizes with Ozz, the substrate-binding component of the muscle-specific ubiquitin ligase complex Ozz-E3. We found that interaction of the two endogenous proteins in the differentiated muscle fibers changes Alix conformation and pro…

Ubiquitin conjugating enzyme E2-N and sequestosome-1 (p62) are components of the ubiquitination process mediated by the malin-laforin E3-ubiquitin li…

2015

11 páginas, 9 figuras.

dsRNA induces apoptosis through an atypical death complex associating TLR3 to caspase-8

2012

Toll-like receptor 3 (TLR3) is a pattern-recognition receptor known to initiate an innate immune response when stimulated by double-stranded RNA (dsRNA). Components of TLR3 signaling, including TIR domain-containing adapter inducing IFN-α (TRIF), have been demonstrated to contribute to dsRNA-induced cell death through caspase-8 and receptor interacting protein (RIP)1 in various human cancer cells. We provide here a detailed analysis of the caspase-8 activating machinery triggered in response to Poly(I:C) dsRNA. Engagement of TLR3 by dsRNA in both type I and type II lung cancer cells induces the formation of an atypical caspase-8-containing complex that is devoid of classical death receptors…

Excitotoxicity in AD is partially caused by the inactivation of APC/C-Cdh1 E3 Ubiquitin Ligase

2013

Oxidative Stress And Ubiquitin Ligases: Their Involvement In Alzheimer’s Disease Pathophysiology

2015

Oxidative stress is a major hallmark in Alzheimer’s Disease. We showed that amyloid beta (Aβ 1-42 ), induces mitochondrial oxidative stress. We focused on dysregulations of ubiquitin ligases in Alzheimer’s and their relation to oxidative stress. The anaphase-promoting complex/cyclosome (APC/C)-Cdh1 ubiquitin ligase has a role as cell cycle regulator in proliferating cells and, recently another role in the regulation the degradation of key glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase-3 has been found (Almeida et al., 2012). Herrero-Mendez et al. observed in 2009 that inhibition of Cdh1 leads to an upregulation of Pfkfb3 in neurons and that this results in the activ…