TY - JOUR
T1 - MARTX effector cross kingdom activation by Golgi-associated ADP-ribosylation factors
AU - Kim, Byoung Sik
AU - Satchell, Karla J.F.
N1 - Funding Information:
We thank Jennifer Wong for technical assistance, and Dr. Heike Fölsch and Dr. Neal Alto for generous providing of GST-Δ17ARF1 and ARF1-strep plasmids respectively. Satchell lab members are thanked for helpful discussion. Core services were provided by the Northwestern Genomics Core for plasmid sequencing, the Northwestern University Center for Advanced Microscopy for microscopy instrumentations, the Tufts University Core Facility for Edman sequencing, and the University of Illinois at Chicago Mass Spectrometry, Metabolomics and Proteomics Facility for tandem mass spectrometry. This work was supported by National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (grant 2013R1A6A3A03024337, to B.S.K.), and by National Institutes of Health grants R01AI092825 and R01AI098369 (to K. J. F. S.).
Publisher Copyright:
© 2016 John Wiley & Sons Ltd
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Vibrio vulnificus infects humans and causes lethal septicemia. The primary virulence factor is a multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin consisting of conserved repeats-containing regions and various effector domains. Recent genomic analyses for the newly emerged V. vulnificus biotype 3 strain revealed that its MARTX toxin has two previously unknown effector domains. Herein, we characterized one of these domains, Domain X (DmXVv). A structure-based homology search revealed that DmXVv belongs to the C58B cysteine peptidase subfamily. When ectopically expressed in cells, DmXVv was autoprocessed and induced cytopathicity including Golgi dispersion. When the catalytic cysteine or the region flanking the scissile bond was mutated, both autoprocessing and cytopathicity were significantly reduced indicating that DmXVv cytopathicity is activated by amino-terminal autoprocessing. Consistent with this, host cell protein export was affected by Vibrio cells producing a toxin with wild-type, but not catalytically inactive, DmXVv. DmXVv was found to localize to Golgi and to directly interact with Golgi-associated ADP-ribosylation factors ARF1, ARF3 and ARF4, although ARF binding was not necessary for the subcellular localization. Rather, this interaction was found to induce autoprocessing of DmXVv. These data demonstrate that the V. vulnificus hijacks the host ARF proteins to activate the cytopathic DmXVv effector domain of MARTX toxin.
AB - Vibrio vulnificus infects humans and causes lethal septicemia. The primary virulence factor is a multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin consisting of conserved repeats-containing regions and various effector domains. Recent genomic analyses for the newly emerged V. vulnificus biotype 3 strain revealed that its MARTX toxin has two previously unknown effector domains. Herein, we characterized one of these domains, Domain X (DmXVv). A structure-based homology search revealed that DmXVv belongs to the C58B cysteine peptidase subfamily. When ectopically expressed in cells, DmXVv was autoprocessed and induced cytopathicity including Golgi dispersion. When the catalytic cysteine or the region flanking the scissile bond was mutated, both autoprocessing and cytopathicity were significantly reduced indicating that DmXVv cytopathicity is activated by amino-terminal autoprocessing. Consistent with this, host cell protein export was affected by Vibrio cells producing a toxin with wild-type, but not catalytically inactive, DmXVv. DmXVv was found to localize to Golgi and to directly interact with Golgi-associated ADP-ribosylation factors ARF1, ARF3 and ARF4, although ARF binding was not necessary for the subcellular localization. Rather, this interaction was found to induce autoprocessing of DmXVv. These data demonstrate that the V. vulnificus hijacks the host ARF proteins to activate the cytopathic DmXVv effector domain of MARTX toxin.
UR - http://www.scopus.com/inward/record.url?scp=84975740684&partnerID=8YFLogxK
U2 - 10.1111/cmi.12568
DO - 10.1111/cmi.12568
M3 - Article
C2 - 26780191
AN - SCOPUS:84975740684
SN - 1462-5814
VL - 18
SP - 1078
EP - 1093
JO - Cellular Microbiology
JF - Cellular Microbiology
IS - 8
ER -