| 1. |
- Sherwood, Victoria, et al.
(författare)
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WNT5A-mediated β-catenin-independent signalling is a novel regulator of cancer cell metabolism.
- 2014
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 35:4, s. 784-794
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Tidskriftsartikel (refereegranskat)abstract
- WNT5A has been identified as an important ligand in the malignant progression of a number of tumours. Although WNT5A signalling is often altered in cancer, the ligand's role as either a tumour suppressor or oncogene varies between tumour types and is a contemporary issue for investigators of β-catenin-independent WNT signalling in oncology. Here, we report that one of the initial effects of active WNT5A signalling in malignant melanoma cells is an alteration in cellular energy metabolism and specifically an increase in aerobic glycolysis. This was found to be at least in part due to an increase in active Akt signalling and lactate dehydrogenase (LDH) activity. The clinical relevance of these findings was strengthened by a strong correlation (P < 0.001) between the expression of WNT5A and LDH isoform V in a cohort of melanocytic neoplasms. We also found effects of WNT5A on energy metabolism in breast cancer cells, but rather than promoting aerobic glycolysis as it does in melanoma, WNT5A signalling increased oxidative phosphorylation rates in breast cancer cells. These findings support a new role for WNT5A in the metabolic reprogramming of cancer cells that is a context- dependent event.
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| 2. |
- Balogh, Istvan, et al.
(författare)
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Analysis of Gas6 in Human Platelets and Plasma.
- 2005
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1524-4636. ; 25:6, s. 1280-1286
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Tidskriftsartikel (refereegranskat)abstract
- Objective - Gas6 is a member of the vitamin K-dependent protein family. Gas6- deficient mice were found to be resistant to thrombosis because of defective platelet function. Mouse Gas6 was demonstrated to be present in platelets and found to be involved in platelet aggregation. The aim of this study was to investigate the presence of Gas6 in human platelets and plasma and determine its role in platelet function. Methods and Results - The presence of Gas6 in human platelets and plasma was analyzed using sensitive immunologic methods. Mass spectrometry and ELISA were used to identify and quantify Gas6 in plasma. Gas6 was demonstrated to be present in human plasma, at a concentration determined to be 13 to 23 ng/mL (0.16 to 0.28 nM). Furthermore, plasma Gas6 levels were found to be lower in patients administered with warfarin. However, Gas6 was undetectable in human platelets. Conclusions - This is the first report to identify and quantify Gas6 in human plasma. However, Gas6 protein was not detected in human platelets, suggesting that any potential platelet-specific function could be because of Gas6 from the circulation. These findings open up new directions regarding the role of Gas6 in normal and pathophysiological situations such as inflammation, autoimmune disease, thrombosis and arteriosclerosis.
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| 3. |
- Cifani, Paolo, et al.
(författare)
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Hunting for Protein Markers of Hypoxia by Combining Plasma Membrane Enrichment with a New Approach to Membrane Protein Analysis
- 2011
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 10:4, s. 1645-1656
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Tidskriftsartikel (refereegranskat)abstract
- Nontransient hypoxia is strongly associated with malignant lesions, resulting in aggressive behavior and resistance to treatment. We present an analysis of mRNA and protein expression changes in neuroblastoma cell lines occurring upon the transition from normoxia to hypoxia. The correlation between mRNA and protein level changes was poor, although some known hypoxia-driven genes and proteins correlated well. We present previously undescribed membrane proteins expressed under hypoxic conditions that are candidates for evaluation as biomarkers.
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| 4. |
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| 5. |
- Hansson, Karin M, et al.
(författare)
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Cysteine-rich secretory proteins in snake venoms form high affinity complexes with human and porcine beta-microseminoproteins.
- 2009
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Ingår i: Toxicon. - : Elsevier BV. - 0041-0101. ; 54, s. 128-137
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Tidskriftsartikel (refereegranskat)abstract
- beta-Microseminoprotein (MSP), a 10kDa protein in human seminal plasma, binds human cysteine-rich secretory protein-3 (CRISP-3) with high affinity. CRISP-3 is a member of the family of CRISPs, which are widespread among animals. In this work we show that human as well as porcine MSP binds catrin, latisemin, pseudecin, and triflin, which are CRISPs present in the venoms of the snakes Crotalus atrox, Laticauda semifasciata, Pseudechis porphyriacus, and Trimeresurus flavoviridis, respectively. The CRISPs were purified from the venoms by affinity chromatography on a human MSP column and their identities were settled by gel electrophoresis and mass spectrometry. Their interactions with human and porcine MSPs were studied with size exclusion chromatography and surface plasmon resonance measurements. The binding affinities at 25 degrees C were between 10(-10)M and 10(-7)M for most of the interactions, with higher affinities for the interactions with porcine MSP compared to human MSP and with Elapidae CRISPs compared to Viperidae CRISPs. The high affinities of the bindings in spite of the differences in amino acid sequence between the MSPs as well as between the CRISPs indicate that the binding is tolerant to amino acid sequence variation and raise the question how universal this cross-species reaction between MSPs and CRISPs is.
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| 8. |
- Hansson, Karin M, et al.
(författare)
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The first gamma-carboxyglutamic acid-containing contryphan - A selective L-type calcium ion channel blocker isolated from the venom of conus marmoreus
- 2004
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 279:31, s. 32453-32463
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Tidskriftsartikel (refereegranskat)abstract
- Contryphans constitute a group of conopeptides that are known to contain an unusual density of post-translational modifications including tryptophan bromination, amidation of the C-terminal residue, leucine, and tryptophan isomerization, and proline hydroxylation. Here we report the identification and characterization of a new member of this family, glacontryphan-M from the venom of Conus marmoreus. This is the first known example of a contryphan peptide carrying glutamyl residues that have been post-translationally carboxylated to {gamma}-carboxyglutamyl (Gla) residues. The amino acid sequence of glacontryphan-M was determined using automated Edman degradation and electrospray ionization mass spectrometry. The amino acid sequence of the peptide is: Asn-Gla-Ser-Gla-Cys-Pro-D-Trp-His-Pro-Trp-Cys. As with most other contryphans, glacontryphan-M is amidated at the C terminus and maintains the five-residue intercysteine loop. The occurrence of a D-tryptophan residue was confirmed by chemical synthesis and HPLC elution profiles. Using fluorescence spectroscopy we demonstrated that the Gla-containing peptide binds calcium with a KD of 0.63 mM. Cloning of the full-length cDNA encoding glacontryphan-M revealed that the primary translation product carries an N-terminal signal/propeptide sequence that is homologous to earlier reported contryphan signal/propeptide sequences up to 10 amino acids preceding the toxin region. Electrophysiological experiments, carried out on mouse pancreatic B-cells, showed that glacontryphan-M blocks L-type voltage-gated calcium ion channel activity in a calcium-dependent manner. Glacontryphan-M is the first contryphan reported to modulate the activity of L-type calcium ion channels.
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| 9. |
- Imperial, Julita S., et al.
(författare)
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Venomous auger snail Hastula (Impages) hectica (Linnaeus, 1758): Molecular phylogeny, foregut anatomy and comparative toxinology
- 2007
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Ingår i: Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. - : Wiley. - 1552-5007 .- 1552-5015. ; 308B:6, s. 744-756
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Tidskriftsartikel (refereegranskat)abstract
- The > 10,000 living venomous marine snail species [superfamily Conoidea Fleming, 1822] include cone snails (Conus), the overwhelming focus of research. Hastula hectica (Linnaeus, 1758), a venomous snail in the family Terebridae Morch, 1852 was comprehensively investigated. The Terebridae comprise a major monophyletic group within Conoidea. H. hectica has a striking radular tooth to inject venom that looks like a perforated spear; in Conus, the tooth looks like a hypodermic needle. H. hectica venom contains a large complement of small disulfide-rich peptides, but with no apparent overlap with Conus in gene superfamilies expressed. Although Conus peptide toxins are densely post-translationally modified, no post-translationally modified amino acids were found in any Hastula venom peptide. The results suggest that different major lineages of venomous molluscs have strikingly divergent toxinological and venom-delivery strategies. J. Exp. Zool. (Mol. Deu. Euol.) 308B: 744- 756, 2007. (c) 2007 Wiley-Liss, Inc.
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| 10. |
- Kang, J, et al.
(författare)
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Total chemical synthesis and NMR characterization of the glycopeptide tx5a, a heavily post-translationally modified conotoxin, reveals that the glycan structure is alpha-D-Gal-(1 -> 3)-alpha-D-GalNAc
- 2004
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 271:23-24, s. 4939-4949
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Tidskriftsartikel (refereegranskat)abstract
- The 13-amino acid glycopeptide tx5a (Gla-Cys-Cys-Gla-Asp-Gly-Trp*-Cys-Cys-Thr*-Ala-Ala-Hyp-OH, where Trp* = 6-bromotryptophan and Thr* = Gal-GalNAc-threonine), isolated from Conus textile, causes hyperactivity and spasticity when injected intracerebral ventricularly into mice. It contains nine post-translationally modified residues: four cysteine residues, two gamma-carboxyglutamic acid residues, and one residue each of 6-bromotryptophan, 4-trans-hydroxyproline and glycosylated threonine. The chemical nature of each of these has been determined with the exception of the glycan linkage pattern on threonine and the stereochemistry of the 6-bromotryptophan residue. Previous investigations have demonstrated that tx5a contains a disaccharide composed of N-acetylgalactosamine (GalNAc) and galactose (Gal), but the interresidue linkage was not characterized. We hypothesized that tx5a contained the T-antigen, beta-D-Gal-(1-->3)-alpha-D-GalNAc, one of the most common O-linked glycan structures, identified previously in another Conus glycopeptide, contalukin-G. We therefore utilized the peracetylated form of this glycan attached to Fmoc-threonine in an attempted synthesis. While the result-ing synthetic peptide (Gla-Cys-Cys-Gla-Asp-Gly-Trp*-Cys-Cys-Thr*-Ala-Ala-Hyp-OH, where Trp* =6-bromotryptophan and Thr* = beta-D-Gal-(1-->3)-alpha-D-GalNAc-threonine) and the native peptide had almost identical mass spectra, a comparison of their RP-HPLC chromatograms suggested that the two forms were not identical. Two-dimensional H-1 homonuclear and C-13-H-1 heteronuclear NMR spectroscopy of native tx5a isolated from Conus textile was then used to determine that the glycan present on tx5a indeed is not the aforementioned T-antigen, but rather alpha-D-Gal-(1-->3)-alpha-D-GalNAc.
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