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Interaction of the adenylate cyclase toxin with complement receptor 3 - Relation of structure and function
Morová, Jana ; Šebo, Peter (advisor) ; Konvalinka, Jan (referee) ; Bezouška, Karel (referee)
4 CoNcl-usroxs PnonucrroN oF tNrEcRtN CDI lb/CDlg F Four fragments of the subunit cDilb were produced and purified and then they were used for immunization of mice and for preparation of specific antibodíes. detected that 52 cells are not able to transport effectively this subunit to cell surface or to secrete its extracellular domain into medium and not even it has a signal peptide specific for 52 cells. Further it has been shorvn, that the level of production of CDl8 subunit was not affected by usage of constitutive or inducible plasmid. ANALYSIS oF THE |NTERÁCTIoN oF RTx ToxINs w|TH p2 INTEGRINS - THE RoLE oF THT, GLYCOSYLATION OF RECEPTORS IN BINDINC ON RTX TOXIN of cell surface glycoproteins, suggesting that cyaA binding to the cell surface- expressed cDllb/cDl8 integrin fully depends on its glycolsylation. It has been a|so demonstrated. that the deglycosylation did not affected ťormation of CD I I b/CD l8 heterodimer or its expression to cell surface. inhibited in the presence ofonly saccharide units that occur in the oligosaccharide chain of integrin molecule. This demonstrates, that cyaA directry recognizes the N-linked oligosaccharide chain ofits p2 integrin recepror. CD l I b/CD I 8-expressing cells. cytotoxic activity of others RTX toxins. l5...
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Interaction of the adenylate cyclase toxin with complement receptor 3 - Relation of structure and function
Morová, Jana
Adenylate cyclase toxin (CyaA) is a key virulence factor of Bordetella pertussiss, the agent of whooping cough (pertussis). CyaA is a secreted bi-functional toxin belonging to the RTX (Repeat in ToXin) family of bacterial cyolysins capable to permeabilize cellular membranes by forming small cation-selective pores. The major activity of CyaA, however, consists in delivery of an adenylate cyclase domain into target cell cytosol, where upon activation by calmodulin it catalyzes uncontrolled conversion of cellular ATP to cAMP, a key signallilng molecule subverting cell functions. Recently, it has been demonstrated that CyaA utilizes the CD11b/CD18 integrin as a specific cellular receptor. The CD11b/CD18 heterodimer is rather promiscuous cell surface molecule, playing an important role in several biological functions of myeloid phagocytic cell, among which are bactericidal functions, such as chemotaxis, phagocytosis, degranulation and superoxide generation. Inhibition of those functions by CyaA action then appears to play an important role in Bordetella virulence. Study of the penetration of CyaA into the cells is important in two reasons. The CyaA toxin is endowed with a unique mechanism of entry into eukaryotic cells that consists in a direct translocation of the catalytic domain across the plasma...
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Interaction of the adenylate cyclase toxin with complement receptor 3 - Relation of structure and function
Morová, Jana ; Šebo, Peter (advisor) ; Konvalinka, Jan (referee) ; Bezouška, Karel (referee)
4 CoNcl-usroxs PnonucrroN oF tNrEcRtN CDI lb/CDlg F Four fragments of the subunit cDilb were produced and purified and then they were used for immunization of mice and for preparation of specific antibodíes. detected that 52 cells are not able to transport effectively this subunit to cell surface or to secrete its extracellular domain into medium and not even it has a signal peptide specific for 52 cells. Further it has been shorvn, that the level of production of CDl8 subunit was not affected by usage of constitutive or inducible plasmid. ANALYSIS oF THE |NTERÁCTIoN oF RTx ToxINs w|TH p2 INTEGRINS - THE RoLE oF THT, GLYCOSYLATION OF RECEPTORS IN BINDINC ON RTX TOXIN of cell surface glycoproteins, suggesting that cyaA binding to the cell surface- expressed cDllb/cDl8 integrin fully depends on its glycolsylation. It has been a|so demonstrated. that the deglycosylation did not affected ťormation of CD I I b/CD l8 heterodimer or its expression to cell surface. inhibited in the presence ofonly saccharide units that occur in the oligosaccharide chain of integrin molecule. This demonstrates, that cyaA directry recognizes the N-linked oligosaccharide chain ofits p2 integrin recepror. CD l I b/CD I 8-expressing cells. cytotoxic activity of others RTX toxins. l5...
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Interaction of the adenylate cyclase toxin with complement receptor 3 - Relation of structure and function
Morová, Jana
Adenylate cyclase toxin (CyaA) is a key virulence factor of Bordetella pertussiss, the agent of whooping cough (pertussis). CyaA is a secreted bi-functional toxin belonging to the RTX (Repeat in ToXin) family of bacterial cyolysins capable to permeabilize cellular membranes by forming small cation-selective pores. The major activity of CyaA, however, consists in delivery of an adenylate cyclase domain into target cell cytosol, where upon activation by calmodulin it catalyzes uncontrolled conversion of cellular ATP to cAMP, a key signallilng molecule subverting cell functions. Recently, it has been demonstrated that CyaA utilizes the CD11b/CD18 integrin as a specific cellular receptor. The CD11b/CD18 heterodimer is rather promiscuous cell surface molecule, playing an important role in several biological functions of myeloid phagocytic cell, among which are bactericidal functions, such as chemotaxis, phagocytosis, degranulation and superoxide generation. Inhibition of those functions by CyaA action then appears to play an important role in Bordetella virulence. Study of the penetration of CyaA into the cells is important in two reasons. The CyaA toxin is endowed with a unique mechanism of entry into eukaryotic cells that consists in a direct translocation of the catalytic domain across the plasma...
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