| First Author | Suzuki T | Year | 2017 |
| Journal | Biochem Biophys Res Commun | Volume | 489 |
| Issue | 2 | Pages | 116-122 |
| PubMed ID | 28533091 | Mgi Jnum | J:251300 |
| Mgi Id | MGI:6103776 | Doi | 10.1016/j.bbrc.2017.05.104 |
| Citation | Suzuki T, et al. (2017) Na(+)/H(+) exchange regulatory factor 1 is required for ROMK1 K(+) channel expression in the surface membrane of cultured M-1 cortical collecting duct cells. Biochem Biophys Res Commun 489(2):116-122 |
| abstractText | The ROMK1 K(+) channel, a member of the ROMK channel family, is the major candidate for the K(+) secretion pathway in the renal cortical collecting duct (CCD). ROMK1 possesses a PDZ domain-binding motif at its C-terminus that is considered a modulator of ROMK1 expression via interaction with Na(+)/H(+) exchange regulatory factor (NHERF) 1 and NHERF2 scaffold protein. Although NHERF1 is a potential binding partner of the ROMK1 K(+) channel, the interaction between NHERF1 and K(+) channel activity remains unclear. Therefore, in this study, we knocked down NHERF1 in cultured M-1 cells derived from mouse CCD and investigated the surface expression and K(+) channel current in these cells after exogenous transfection with EGFP-ROMK1. NHERF1 knockdown resulted in reduced surface expression of ROMK1 as indicated by a cell biotinylation assay. Using the patch-clamp technique, we further found that the number of active channels per patched membrane and the Ba(2+)-sensitive whole-cell K(+) current were decreased in the knockdown cells, suggesting that reduced K(+) current was accompanied by decreased surface expression of ROMK1 in the NHERF1 knockdown cells. Our results provide evidence that NHERF1 mediates K(+) current activity through acceleration of the surface expression of ROMK1 K(+) channels in M-1 cells. |
