Nuclear trafficking of the anti-apoptotic Coxiella burnetii effector protein AnkG requires binding to p32 and Importin-α1.
The obligate intracellular bacterium Coxiella burnetii causes the zoonotic disease Q-fever. Coxiella pathogenesis depends on a functional type IV secretion system (T4SS). The T4SS effector AnkG inhibits pathogen-induced host cell apoptosis, which is believed to be important for the establishment of a persistent infection. However, the mode of action of AnkG is not fully understood. We have previously demonstrated that binding of AnkG to p32 is crucial for migration of AnkG into the nucleus and that nuclear localization of AnkG is essential for its anti-apoptotic activity. Here, we compared the activity of AnkG from the C. burnetii strains Nine Mile and Dugway. Although there is only a single amino acid exchange at residue 11, we observed a difference in anti-apoptotic activity and nuclear migration. Mutation of amino acid 11 to glutamic acid, threonine or valine results in AnkG mutants that had lost the anti-apoptotic activity and the ability to migrate into the nucleus. We identified Importin-α1 to bind to AnkG, but not to the mutants and concluded that binding of AnkG to p32 and Importin-α1 is essential for migration into the nucleus. Also during Coxiella infection binding of AnkG to p32 and Importin-α1 is crucial for nuclear localization of AnkG.
Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Wasserturmstrasse 3-5, D-91054, Erlangen, Germany.
Walter
W
Schäfer
Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Wasserturmstrasse 3-5, D-91054, Erlangen, Germany.
Rita A
RA
Eckart
Lehrstuhl für Biotechnik, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 91, D-91052, Erlangen, Germany.
Benedikt
B
Schmid
Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Wasserturmstrasse 3-5, D-91054, Erlangen, Germany.
Hasret
H
Cagköylü
Lehrstuhl für Biotechnik, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 91, D-91052, Erlangen, Germany.
Kerstin
K
Hof
Lehrstuhl für Biotechnik, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 91, D-91052, Erlangen, Germany.
Yves A
YA
Muller
Lehrstuhl für Biochemie, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058, Erlangen, Germany.
Bushra
B
Amin
Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Wasserturmstrasse 3-5, D-91054, Erlangen, Germany.
Anja
A
Lührmann
D021581:Active Transport, Cell Nucleus; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D016997:Coxiella burnetii / Q000502:physiology*; D004252:DNA Mutational Analysis; D054884:Host-Pathogen Interactions; D006801:Humans; D024101:Mitochondrial Proteins / Q000378:metabolism*; D011485:Protein Binding; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D028901:alpha Karyopherins / Q000378:metabolism*
C000621609:AnkG protein, Coxiella burnetii; D001426:Bacterial Proteins; C087299:C1QBP protein, human; D002352:Carrier Proteins; D024101:Mitochondrial Proteins; D037521:Virulence Factors; D028901:alpha Karyopherins; C087978:karyopherin alpha 2