| 1. |
- Escribano, Julio, et al.
(författare)
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Identification of retinol as one of the protein HC chromophores
- 1988
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 155:3, s. 1424-1429
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Tidskriftsartikel (refereegranskat)abstract
- Protein HC (alias alpha 1-microglobulin) contains so far unidentified yellow-brown fluorescent chromophores. Several preparations of human protein HC were extracted with hexane. Most of the extracts contained a substance which, upon reversed-phase HPLC, co-eluted with all-trans- retinol and had an absorption spectrum identical to that of retinol. The substance was also, like retinol, destroyed by exposure to ultraviolet light and acid pH. These observations strongly support the proposal that protein HC is a member of the newly defined lipocalin protein superfamily. The highest retinol-protein HC molar ratio of the investigated protein HC preparations was 1.6 x 10(-3) indicating that retinol is not the only ligand bound to protein HC. This was confirmed by comparing the absorption spectrum of protein HC before and after hexane extraction.
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| 2. |
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| 3. |
- López-Otin, C, et al.
(författare)
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Neutral microprotein, a novel human plasma and urinary protein associated with a yellow-brown chromophore. Isolation from protein HC preparations and partial characterization
- 1983
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 117:1, s. 9-202
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Tidskriftsartikel (refereegranskat)abstract
- An apparently novel human plasma and urinary protein of low molecular weight was isolated from several highly purified preparations of protein HC by gel chromatography and high voltage electrophoresis with a yield of about 8 mg/g. The protein has a molecular weight of about 20,000, neutral electrophoretic mobility at pH 6.5 and a high content of half-cystine. It is associated with a yellow-brown chromophore like protein HC and could be demonstrated in all investigated preparations of isolated human, rabbit and guinea-pig protein HC and alpha 1-microglobulin.
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| 4. |
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| 5. |
- 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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| 6. |
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| 7. |
- 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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| 8. |
- 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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| 9. |
- 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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| 10. |
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