In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 109, No. 24 ( 2012-06-12), p. 9581-9586
Abstract:
Subversion of host organism cAMP signaling is an efficient and widespread mechanism of microbial pathogenesis. Bartonella effector protein A (BepA) of vasculotumorigenic Bartonella henselae protects the infected human endothelial cells against apoptotic stimuli by elevation of cellular cAMP levels by an as yet unknown mechanism. Here, adenylyl cyclase (AC) and the α-subunit of the AC-stimulating G protein (Gαs) were identified as potential cellular target proteins for BepA by gel-free proteomics. Results of the proteomics screen were evaluated for physical and functional interaction by: ( i ) a heterologous in vivo coexpression system, where human AC activity was reconstituted under the regulation of Gαs and BepA in Escherichia coli ; ( ii ) in vitro AC assays with membrane-anchored full-length human AC and recombinant BepA and Gαs; ( iii ) surface plasmon resonance experiments; and ( iv ) an in vivo fluorescence bimolecular complementation-analysis. The data demonstrate that BepA directly binds host cell AC to potentiate the Gαs-dependent cAMP production. As opposed to the known microbial mechanisms, such as ADP ribosylation of G protein α-subunits by cholera and pertussis toxins, the fundamentally different BepA-mediated elevation of host cell cAMP concentration appears subtle and is dependent on the stimulus of a G protein-coupled receptor-released Gαs. We propose that this mechanism contributes to the persistence of Bartonella henselae in the chronically infected vascular endothelium.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1117651109
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2012
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
