Search

The structural changes presented by the Cry1Ac toxin upon binding to the APN receptor and the role of its interaction in toxin membrane insertion is analyzed. The analysis did not reveal major structural changes in the pore-forming domain I upon Ga1NAc binding, but showed that sugar interaction enhanced membrane insertion of soluble pre-pore oligomeric structure which permits to propose a model in which the interaction of Cry1Ac pre-pore oligomer with APN receptor facilitates membrane insertion and pore formation.

A study was conducted to examine the role of Trp residues in the structure and function of Cry1Ab toxin, produced by Bacillus thuringiensis. The results show that W65 and W316 are important for insecticidal activity of the toxin since their replacement by Phe reduced toxicity against Manduca sexta.

A study was conducted on the identification of an S-layer protein by the screening of Bacillus thuringiensis strains for activity against the coleopteran pest Epilachna varivestis. It was observed that the S-layer protein is directly involved in toxicity to a coleopteran past.

Neisseria meningitidis (meningococcus) is an invasive bacterial pathogen that colonizes human vessels, causing thrombotic lesions and meningitis. Establishment of tight interactions with endothelial cells is crucial for meningococci to resist haemodynamic forces. Two endothelial receptors, CD147 and the β2-adrenergic receptor (β2AR), are sequentially engaged by meningococci to adhere and promote signalling events leading to vascular colonization, but their spatiotemporal coordination is unknown. Here we report that CD147 and β2AR form constitutive hetero-oligomeric complexes. The scaffolding protein α-actinin-4 directly binds to the cytosolic tail of CD147 and governs the assembly of CD147-β2AR complexes in highly ordered clusters at bacterial adhesion sites. This multimolecular assembly process increases the binding strength of meningococci to endothelial cells under shear stress, and creates molecular platforms for the elongation of membrane protrusions surrounding adherent bacteria. Thus, the specific organization of cellular receptors has major impacts on host-pathogen interaction. [ABSTRACT FROM AUTHOR]

Neisseria meningitidis (meningococcus) is an invasive bacterial pathogen that colonizes human vessels, causing thrombotic lesions and meningitis. Establishment of tight interactions with endothelial cells is crucial for meningococci to resist haemodynamic forces. Two endothelial receptors, CD147 and the β2-adrenergic receptor (β 2 AR), are sequentially engaged by meningococci to adhere and promote signalling events leading to vascular colonization, but their spatiotemporal coordination is unknown. Here we report that CD147 and β 2 AR form constitutive hetero-oligomeric complexes. The scaffolding protein α-actinin-4 directly binds to the cytosolic tail of CD147 and governs the assembly of CD147-β 2 AR complexes in highly ordered clusters at bacterial adhesion sites. This multimolecular assembly process increases the binding strength of meningococci to endothelial cells under shear stress, and creates molecular platforms for the elongation of membrane protrusions surrounding adherent bacteria. Thus, the specific organization of cellular receptors has major impacts on host-pathogen interaction.