Abstract: SA-PO1028
MAGE-D2 Regulated Na-Cl Cotransporter Through Chaperon-Dependent ERAD
Session Information
- Fluid and Electrolytes: Basic - II
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid and Electrolytes
- 901 Fluid and Electrolytes: Basic
Authors
- Yang, Sung-Sen, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Lin, Chien-Ming, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Kömhoff, Martin, Philipps University Marburg, Marburg, Germany
- Lin, Shih-Hua P., Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
Background
Mutations in MAGE-D2 gene, encoded in X-chromosome, was reported to associate with transient antenatal Batter’s syndrome with severe polyhydramnios. Reduced Na-K-2Cl cotransporter 2 (NKCC2) and Na-Cl cotransporter (NCC) was observed in the renal tubules of affected male patients.
Methods
To explore the role of mutant MAGE-D2 in the kidney, we created mutant Mage-d2 knock-in (KI) mice and examined the possible molecular mechanisms in vitro.
Results
Three strains of disease-mutant Mage-d2 (c274dupA, Y346X and A495G) KI mice were generated and only female A495G/+ mice could be produced from chimera mouse. By sonography, some embryos with polyhydramnios were found in A495G/+ female mice at E15.5D. Compared with the WT embryos, more amniotic fluid amount in male A495G/+ embryos but not female A495G/+ embryos was observed. The osmolarity of the amniotic fluid was not significant between female or male WT and A495G/+ embryos. When the different types of Mage-d2 cDNA [WT, c274dupA (truncated protein), Y346X (truncated protein) and A495G (missense full-length protein)] was transfected into the HEK293 cells, Y346X and A495G Mage-d2 showed interruption of the cell cycles in the G2/M phase and reduction of the abundance of NCC. Immunoprecipitation study revealed NCC could interact with WT and A495G Mage-D2 instead of truncated c274dupA and Y346X Mage-D2 proteins. Y346X and A495G Mage-d2 also reduce the expression of HSP40, HSP90 and CHIP. These chaperon proteins were reported to form a complex and play a role in the ER-associated degradation (ERAD) of the NCC.
Conclusion
These results suggested that Mage-D2 might affect the cell cycles of renal tubular cells and the NCC expression through regulating ERAD chaperon proteins.
Funding
- Government Support - Non-U.S.