Third activity of Bordetella adenylate cyclase (AC) toxin-hemolysin - Membrane translocation of AC domain polypeptide promotes calcium influx into CD11b(+) monocytes independently of the catalytic and hemolytic activities

Abstract

The Bordetella adenylate cyclase toxin-hemolysin (CyaA) targets phagocytes expressing the alpha(M)beta(2) integrin (CD11b/CD18), permeabilizes their membranes by forming small cation-selective pores, and delivers into cells a calmodulin-activated adenylate cyclase (AC) enzyme that dissipates cytosolic ATP into cAMP. We describe here a third activity of CyaA that yields elevation of cytosolic calcium concentration ([Ca2+](i)) in target cells.

Keywords

• Adenylate Cyclase Toxin
• Bordetella pertussis
• Calcium influx
• Protein translocation