TY - JOUR
T1 - Correlation Between Attenuation of Protein Disulfide Isomerase Activity Through S-Mercuration and Neurotoxicity Induced by Methylmercury
AU - Makino, Kento
AU - Okuda, Kosaku
AU - Sugino, Eisuke
AU - Nishiya, Tadashi
AU - Toyama, Takashi
AU - Iwawaki, Takao
AU - Fujimura, Masatake
AU - Kumagai, Yoshito
AU - Uehara, Takashi
N1 - Funding Information:
We thank Aki Tsuboi and Yoko Okamoto for providing technical assistance. This work was supported in part by Grants-in Aid for Scientific Research on Challenging Exploratory Research 25670029 and Scientific Research B 22310093 from the Japan Ministry of Education, Culture, Sports and Technology (MEXT), by the Takeda Science Foundation, the Smoking Research Foundation, and the Okayama Medical Foundation.
Publisher Copyright:
© 2014, Springer Science+Business Media New York.
PY - 2014/2
Y1 - 2014/2
N2 - Methylmercury (MeHg), an environmental pollutant, causes neuronal death via endoplasmic reticulum (ER) stress; however, the precise mechanism is not fully understood. The aim of this study was to elucidate the possible mechanism of MeHg-induced neurotoxicity. Treatment with MeHg resulted in a loss of cell viability in a concentration-dependent manner accompanying the expression of ER stress marker genes in human neuroblastoma SH-SY5Y cells. We next attempted to identify a target protein for MeHg in the ER. MeHg covalently modified protein disulfide isomerase (PDI), which is important for disulfide bond formation in nascent proteins in the ER lumen. S-Nitrosylation of the catalytic domains of PDI by nitric oxide was attenuated up to 50 % by a MeHg challenge in cells. The MeHg-modified C-terminal catalytic domain in PDI was detected by MALDI-TOF/MS. Furthermore, treatment with MeHg significantly attenuated the enzymatic activity of PDI. Taken together, these observations suggest that MeHg results in ER stress and following the unfolded protein response pathway via ER dysfunction due to S-mercuration of the C-terminus of PDI.
AB - Methylmercury (MeHg), an environmental pollutant, causes neuronal death via endoplasmic reticulum (ER) stress; however, the precise mechanism is not fully understood. The aim of this study was to elucidate the possible mechanism of MeHg-induced neurotoxicity. Treatment with MeHg resulted in a loss of cell viability in a concentration-dependent manner accompanying the expression of ER stress marker genes in human neuroblastoma SH-SY5Y cells. We next attempted to identify a target protein for MeHg in the ER. MeHg covalently modified protein disulfide isomerase (PDI), which is important for disulfide bond formation in nascent proteins in the ER lumen. S-Nitrosylation of the catalytic domains of PDI by nitric oxide was attenuated up to 50 % by a MeHg challenge in cells. The MeHg-modified C-terminal catalytic domain in PDI was detected by MALDI-TOF/MS. Furthermore, treatment with MeHg significantly attenuated the enzymatic activity of PDI. Taken together, these observations suggest that MeHg results in ER stress and following the unfolded protein response pathway via ER dysfunction due to S-mercuration of the C-terminus of PDI.
KW - Endoplasmic reticulum stress
KW - Methylmercury
KW - Neurotoxicity
KW - Protein disulfide isomerase
KW - S-mercuration
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U2 - 10.1007/s12640-014-9494-8
DO - 10.1007/s12640-014-9494-8
M3 - Article
C2 - 25288108
AN - SCOPUS:84921937120
SN - 1029-8428
VL - 27
SP - 99
EP - 105
JO - Neurotoxicity Research
JF - Neurotoxicity Research
IS - 2
ER -