In this paper we describe the potential of theenhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive bl...
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In this paper we describe the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive black-holes. eXTP has the unique capability of using advanced "spectral-timing-polarimetry" techniques to analyze the rapid variations with three orthogonal diagnostics of the flow and its geometry, yielding unprecedented insight into the inner accreting regions, the effects of strong field gravity on the material within them and the powerful outflows which are driven by the accretion process.
AIM:To study the binding of connective tissue growth factor(CTGF) to cystine knot-containing ligands and how this impacts platelet-derived growth factor(PDGF)-B signaling. MeTHODS:The binding strengths of CTGF to cyst...
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AIM:To study the binding of connective tissue growth factor(CTGF) to cystine knot-containing ligands and how this impacts platelet-derived growth factor(PDGF)-B signaling. MeTHODS:The binding strengths of CTGF to cystine knot-containing growth factors including vascular en-dothelial growth factor(VeGF)-A,PDGF-B,bone morphogenetic protein(BMP)-4,and transforming growth factor(TGF)-β1 were compared using the LexA-based yeast two-hybrid system. eYG48 reporter strain that carried a wild-type LeU2 gene under the control of Lex A operators and a lac Z reporter plasmid(p80plac Z) containing eight high affinity Lex A binding sites were used in the yeast two-hybrid analysis. Interactions between CTGF and the tested growth factors were evaluated based on growth of transformed yeast cells on selective media and colorimetric detection in a liquid β-galactosidase activity assay. Dissociation constants of CTGF to VeGF-A isoform 165 or PDGF-BB homo-dimer were measured in surface plasma resonance(SPR) analysis. CTGF regulation in PDGF-B presentation to the PDGF receptor β(PDGFRβ) was also quantitatively assessed by the SPR analysis. Combinational effects of CTGF protein and PDGF-BB on activation of PDGFRβ and downstream signaling molecules eRK1/2 and AKT were assessed in rabbit corneal fibroblast cells by Western analysis. ReSULTS:In the LexA-based yeast two-hybrid system,cystine knot motifs of tested growth factors were fused to the activation domain of the transcriptional factor GAL4 while CTGF was fused to the DNA binding domain of the bacterial repressor protein Lex A. Yeast cotransformants containing corresponding fusion proteins for CTGF and all four tested cystine knot motifs survived on selective medium containing galactose and raffinose but lacking histidine,tryptophan,and uracil. In liquid β-galactosidase assays,CTGF expressing cells that were co-transformed with the cystine knot of VeGF-A had the highest activity,at 29.88 ± 0.91 fold above controls(P ells conta
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