| 1. |
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| 2. |
- Abramczyk, Olga, et al.
(författare)
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The protein kinase 60S is a free catalytic CK2alpha' subunit and forms an inactive complex with superoxide dismutase SOD1
- 2003
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 307:1, s. 31-40
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Tidskriftsartikel (refereegranskat)abstract
- The 60S ribosomes from Saccharomyces cerevisiae contain a set of acidic P-proteins playing an important role in the ribosome function. Reversible phosphorylation of those proteins is a mechanism regulating translational activity of ribosomes. The key role in regulation of this process is played by specific, second messenger-independent protein kinases. The PK60S kinase was one of the enzymes phosphorylating P-proteins. The enzyme has been purified from yeast and characterised. Pure enzyme has properties similar to those reported for casein kinase type 2. Peptide mass fingerprinting (PMF) has identified the PK60S as a catalytic alpha(') subunit of casein kinase type 2 (CK2alpha(')). Protein kinase activity is inhibited by SOD1 and by highly specific CK2 inhibitor-4,5,6,7-tetrabromo-benzotriazole (TBBt). The possible mechanism of regulation of CK2alpha(') activity in stress conditions, by superoxide dismutase in regulation of 80S-ribosome activity, is discussed.
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| 3. |
- Althini, Susanna, et al.
(författare)
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Bone morphogenetic protein signalling in NGF-stimulated PC12 cells
- 2003
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 307:3, s. 632-639
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Tidskriftsartikel (refereegranskat)abstract
- Bone morphogenetic proteins (BMPs) are shown to potentiate NGF-induced neuronal differentiation in PC12 phaeochromocytoma cells grown on collagen under low-serum conditions. Whereas, cell bodies remained rounded in control medium or with only BMPs present, addition of BMP4 or BMP6 robustly increased the neuritogenic effect of NGF within 2 days. NGF-increased phosphorylation of p44(Erk1) and p42(Erk2) between 2 and 24h was unaffected by addition of BMP6. PC12 cells transfected with the SBE(4x)-luc reporter showed that BMP4 significantly increased receptor-activated Smad activity. Expression of constitutively active BMP receptor ALK2 activating Smad1 and Smad5 resulted in a strong increase in the SBE(4x)-luc reporter response. Adding the inhibitory Smad7 drastically reduced this signal. In contrast to wild-type (wt) Smad5, a Smad5 variant lacking five Erk phosphorylation sites in the linker region (designated Smad5/5SA) showed a strong background transcriptional activity. A fusion construct (Gal4-Smad5/5SA) was also highly transcriptionally active. Addition of the MEK inhibitor U0126 to PC12 cells expressing Gal4-Smad5/wt did not increase background transcriptional activity. However, upon activation by constitutively active ALK2 both Gal4-Smad5/wt and Gal4-Smad5/5SA strongly stimulated transcription. The data show that serine residues of the linker region of Smad5 reduce spontaneous transcriptional activity and that NGF-activated Erk does not antagonise BMP signalling at this site. Hence, NGF and BMP signals are likely to interact further downstream at the transcriptional level in neuronal differentiation of the PC12 cells.
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| 4. |
- Andersson, Charlotte, et al.
(författare)
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Activation of CFTR by genistein in human airway epithelial cell lines
- 2003
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 308:3, s. 518-522
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Tidskriftsartikel (refereegranskat)abstract
- Cystic fibrosis (CF) is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel expressed in epithelial cells. The effects of genistein and 4-phenylbutyrate (PBA) on CFTR were studied in three human airway epithelial cell lines expressing wild-type or DeltaF508 CFTR: Calu-3, CFSMEo-, and CFBE41o- cells. The cells were loaded with the fluorescent dye N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE) and chloride efflux was studied. Forskolin and 3-isobutyl-1-methylxanthine (IBMX) induced chloride efflux in Calu-3 cells but not in CF lines. Genistein (2.5-50 microM) alone was able to induce chloride efflux in all cell lines. Genistein did not enhance the effect of forskolin and IBMX. PBA had little or no effect on genistein-induced chloride efflux. The effect of genistein seen at low concentrations makes genistein interesting for possible pharmacological treatment of CF, since it is known that similar concentrations can be obtained in plasma by a soy-rich diet.
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| 5. |
- Andersson, Karin, et al.
(författare)
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Only amyloidogenic inermediates of transthyretin induce apoptosis
- 2002
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Carolina Academic Press. - 0006-291X .- 1090-2104. ; 294:2, s. 309-314
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Tidskriftsartikel (refereegranskat)abstract
- In diseases like Alzheimer's disease and familial amyloidotic polyneuropathy (FAP) amyloid deposits co-localize with areas of neurodegeneration. FAP is associated with mutations of the plasma protein transthyretin (TTR). We can here show an apoptotic effect of amyloidogenic mutants of TTR on a human neuroblastoma cell line. Toxicity could be blocked by catalase indicating a free oxygen radical dependent mechanism. The toxic effect was dependent on the state of aggregation and unexpectedly mature fibrils from FAP-patients who failed to exert an apoptotic response. Morphological studies revealed a correlation between toxicity and the presence of immature amyloid. Thus, we can show that toxicity is associated with early stages of fibril formation and propose that mature full-length fibrils represent an inert end stage, which might serve as a rescue mechanism.
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| 6. |
- Andrae, Johanna, et al.
(författare)
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Platelet-derived growth factor-B and -C and active alpha-receptors in medulloblastoma cells.
- 2002
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Ingår i: Biochemical and biophysical research communications. - 0006-291X .- 1090-2104. ; 296:3, s. 604-11
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Tidskriftsartikel (refereegranskat)abstract
- The malignant childhood brain tumor medulloblastoma belongs to the group of primitive neuroectodermal tumours (PNETs). Medulloblastomas are thought to arise from remnants of the transient external germinal layer in the cerebellum. Proliferation, differentiation, and motility of cells in the central nervous system are regulated by growth factors, e.g., platelet-derived growth factor (PDGF). Recently, it was shown that higher level of PDGF alpha-receptor expression is characteristic of metastatic medulloblastomas. We have investigated five medulloblastoma/PNET cell lines and found that the PDGF alpha-receptor is actively signalling in most of them, an activity most likely driven by endogenously produced PDGF-C. PDGF-C is normally present in cells of the developing external germinal layer and our results are consistent with the idea that medulloblastomas are derived from such cells undergoing early neuronal differentiation. Moreover, the expression of PDGF and its receptors was associated with neuronal characteristics, but not with high levels of c-myc expression in the medullablastoma cells.
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| 7. |
- Brannvall, K, et al.
(författare)
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Cystatin-B is expressed by neural stem cells and by differentiated neurons and astrocytes
- 2003
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0006-291X .- 1090-2104. ; 308:2, s. 369-374
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Tidskriftsartikel (refereegranskat)abstract
- Mutation in the gene encoding cystatin-B (CSTB) has been shown to cause progressive myoclonus epilepsy. Mice with a gene deletion of CSTB exhibit increased apoptosis of specific neurons but the physiological role of CSTB in brain cells is not fully understood. In the present study, we have examined the expression of CSTB in neural stem cells (NSC) and in differentiating mature brain cells. The results show that CSTB is present in embryonic and adult NSC and in the neuroepithelium. CSTB was expressed by both neurons and glial cells differentiated from NSC and in hippocampal cultures. CSTB localized mainly to the nucleus in NSC and in neurons, whilst in astrocytes CSTB was also in the cytoplasm. Double labeling showed that CSTB was present in the lysosomes in glial cells. The results demonstrate a nuclear expression of CSTB in NSC and in neurons, suggesting novel function for this molecule. (C) 2003 Elsevier Inc. All rights reserved.
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| 8. |
- Brändström, Helena, et al.
(författare)
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A single nucleotide polymorphism in the promoter region of the human gene for osteoprotegerin is related to vascular morphology and function
- 2002
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 293:1, s. 13-17
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Tidskriftsartikel (refereegranskat)abstract
- Osteoprotegerin (OPG) is a secreted member of the tumor necrosis factor receptor family, and has previously been shown to regulate bone mass by inhibiting osteoclast differentiation and activation. Recent evidence indicates that OPG also plays a role in the vascular system, since ablation of the OPG gene in mice results in calcification of the aorta and renal arteries, and association has been found between serum levels of OPG and cardiovascular mortality. This study presents a novel single nucleotide polymorphism, a T/C transition located 129 bp upstream the TATA-box of the human OPG gene, detected by sequence analysis. The OPG genotype was determined by restriction fragment length polymorphism in a cohort consisting of 59 healthy subjects. The intima-media thickness (IMT) in the common carotid artery and maximal post-ischemic forearm blood flow (FBF) were investigated. Subjects with the CC genotype showed a significantly increased IMT (p<0.05) and a concommitantly reduced maximal FBF (p<0.01) as compared to those with the T allele. Thus, our results show that the polymorphism in the promoter region of OPG is associated with both vascular morphology and function in apparently healthy subjects.
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| 9. |
- Czene, S, et al.
(författare)
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DNA fragmentation and morphological changes in apoptotic human lymphocytes
- 2002
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 294:4, s. 872-878
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Tidskriftsartikel (refereegranskat)abstract
- Cell suspensions enriched in cells at various stages of apoptosis were obtained by separation of irradiated human peripheral blood lymphocytes on density gradients at different post-irradiation times. The state of DNA fragmentation in the cells was determined by comet assay and pulsed field gel electrophoresis. The morphologically distinguishable features of apoptosis such as chromatin condensation and cell shrinkage correlated with discrete stages of DNA fragmentation. It was found that greater than or equal to50kbp fragmentation of DNA occurs already in cells of normal density whereas the subsequent DNA fragmentation onto fragments <50 kbp occurs in parallel with cell shrinkage and simultaneous increase in cell density. The observed stages of DNA fragmentation seem to be separated in time that could allow in case of abortive apoptosis formation of chromosomal aberrations.
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| 10. |
- Edlund, Bror, et al.
(författare)
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Amino acid sequence at the phosphorylated site of rat liver pyruvate kinase
- 1975
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 67:4, s. 1516-1521
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Tidskriftsartikel (refereegranskat)abstract
- One dominating peptic phosphopeptide, Asx-Thr-Lys-Gly-Pro-Glx-Ile-Glx-Thr-Gly-Val-Leu-Arg-Arg-Ala-(32P)SerP-Val-Ala-Glx-Leu, was obtained from rat liver pyruvate kinase (type L) phosphorylated by cyclic 3′,5′-AMP-stimulated protein kinase from the same tissue. The sequence around the phosphorylated serine residue is similar to that of a corresponding but smaller peptic phosphopeptide previously isolated from pig liver (type L) pyruvate kinase, Leu-Arg-Arg-Ala-(32P)SerP-Leu.
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