Search results for "tyrosine phosphatases"
showing 10 items of 22 documents
Receptor protein-tyrosine phosphatases: origin of domains (catalytic domain, Ig-related domain, fibronectin type III module) based on the sequence of…
2001
Abstract Reversible tyrosine phosphorylation of proteins is one of the major regulatory physiological events in response to cell-cell- and cell-matrix contact in Metazoa. Previously it was documented that the tyrosine phosphorylating enzymes, the tyrosine kinases (TKs), are autapomorphic characters of Metazoa, including sponges. In this paper the tyrosine dephosphorylating enzymes, the protein-tyrosine phosphatases (PTPs), are studied which can be grouped into two subfamilies, the soluble PTPs and the receptor PTPs (RPTPs). PTPs are characterized by one PTPase domain which interestingly comprises sequence similarity to yeast PTPs. In contrast to the PTPs, the RPTPs – which have been found o…
Redox signaling in acute pancreatitis
2015
Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On th…
Young woman with Branchio-Oto-Renal Syndrome and a novel mutation in the EYA-1 gene
2011
Branchio-oto-renal (BOR) syndrome is an autosomal dominant disease clinically characterized by the coexistence of some or all of the following major disorders: deafness, cervical branchial fistulae, preauricular pits, and renal abnormalities. Most families with BOR syndrome have mutations on the EYA-1 gene on chromosome 8q. We present the case of a 23-year-old Italian woman without a familial history of BOR syndrome. The patient, who had hearing loss and a history of surgeries for correction of bilateral cervical branchial fistulae and bilateral preauricular pits, presented with renal impairment, hypertension and overt proteinuria. DNA sequencing showed a novel heterozygous mutation 1420-14…
Glucocorticoids inhibit MAP kinase via increased expression and decreased degradation of MKP-1
2001
Glucocorticoids inhibit the proinflammatory activities of transcription factors such as AP-1 and NF-kappa B as well as that of diverse cellular signaling molecules. One of these signaling molecules is the extracellular signal-regulated kinase (Erk-1/2) that controls the release of allergic mediators and the induction of proinflammatory cytokine gene expression in mast cells. The mechanism of inhibition of Erk-1/2 activity by glucocorticoids is unknown. Here we report a novel dual action of glucocorticoids for this inhibition. Glucocorticoids increase the expression of the MAP kinase phosphatase-1 (MKP-1) gene at the promoter level, and attenuate proteasomal degradation of MKP-1, which we re…
Different protein turnover of interleukin-6-type cytokine signalling components.
1999
Interleukin (IL)-6 and IL-6-type cytokines signal through the gp130/Jak/STAT signal transduction pathway. The key components involved are the signal transducing receptor subunit gp130, the Janus kinases Jak1, Jak2 and Tyk2, STAT1 and STAT3 of the family of signal transducers and activators of transcription, the protein tyrosine phosphatase SHP2 and the suppressors of cytokine signalling SOCS1, SOCS2 and SOCS3. Whereas considerable information has been accumulated concerning the time-course of activation for the individual signalling molecules, data on the availability of the proteins involved in IL-6-type cytokine signal transduction are scarce. Nevertheless, availability of these molecules…
Role of PTPRJ genotype in papillary thyroid carcinoma risk
2010
The strong genetic predisposition to papillary thyroid carcinoma (PTC) might be due to a combination of low-penetrance susceptibility variants. Thus, the research into gene variants involved in the increase of susceptibility to PTC is a relevant field of investigation. The gene coding for the receptor-type tyrosine phosphatase PTPRJ has been proposed as a cancer susceptibility gene, and its role as a tumor suppressor gene is well established in thyroid carcinogenesis. In this study, we want to ascertain the role of PTPRJ genotype in the risk for PTC. We performed a case–control study in which we determined the PTPRJ genotype for the non-synonymous Gln276Pro and Asp872Glu polymorphisms by PC…
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 …
Oxidative stress, a new hallmark in the pathophysiology of Lafora progressive myoclonus epilepsy
2015
12 páginas, 4 figuras, 1 tabla
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.
Light-induced resistance of the keratin network to the filament-disrupting tyrosine phosphatase inhibitor orthovanadate.
2003
Epidermal keratinocytes respond to low-dose light irradiation by inducing signaling cascades that lead to long-term effects on gene transcription thereby protecting cells against damage. In contrast, little is known about immediate light-induced alterations of structural proteins. We have made the intriguing observation that light produces fundamental changes in the properties of the keratin filament system of cultured epidermoid A-431 cells. A short light exposure (1–10 min) causes the keratin cytoskeleton to become immediately resistant to the tyrosine phosphatase inhibitor orthovanadate, which otherwise disrupts the keratin filament network completely in just a few minutes. This protecti…