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Inhibition of Sodium Hydrogen Exchanger 1 Palmitoylation is Associated with Suppression of Cell Migration
Author(s) -
Hovde Moriah J,
Kooiker Amanda J,
Rastedt Danielle E,
Provost Joseph J,
Vaughan Roxanne A,
Wallert Mark A,
Foster James D
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.602.13
Subject(s) - palmitoylation , sodium–hydrogen antiporter , microbiology and biotechnology , protein kinase a , chemistry , intracellular , biochemistry , biology , kinase , sodium , cysteine , enzyme , organic chemistry
The sodium hydrogen exchanger isoform 1 (NHE1) is involved in many cellular processes including regulation of intracellular pH, coordination of cell migration, control of cell volume, and anchoring protein interactions at the cell membrane. NHE1 is integral plasma membrane protein with 12 transmembrane spanning domains that exchanges an intracellular proton for an extracellular sodium ion. NHE1 is implicated in neoplastic transformation leading to tumorgenesis where the exchanger localizes to the leading edge of migrating cells initiating forward movement of cells indicating a potential role for NHE1 in cancer progression. NHE1 is regulated by many factors including multiple protein‐protein interactions and a number of phosphorylation events. Recent reports indicate that many proteins identified to play key roles in cancer are regulated by palmitoylation. S‐palmitoylation is a dynamic and reversible posttranslational modification, in which the protein undergoes cycles of palmitoylation and depalmitoylation, catalyzed by palmitoyl acyltransferases (PATs) and acyl protein thioesterases (APTs), respectively. Palmitoylation is known to regulate protein trafficking, membrane microlocalization and protein‐protein interactions. These findings prompted us to investigate the presence of this modification on NHE1 using acyl‐biotinyl exchange (ABE), an in vitro assay for post‐hoc detection of endogenous palmitoylation, which revealed that NHE1 is palmitoylated. To further evaluate the nature of NHE1 palmitoylation we treated Chinese hamster lung fibroblasts expressing human NHE1 (PSN) with the irreversible PAT inhibitor 2‐bromopalmitate (2BP). We found 2BP suppresses NHE1 palmitoylation in both a time and dose dependent manner. Additionally, PSN cell migration assessed using electric cell‐substrate impedance sensing was inhibited by 2BP in a manner consistent with the degree of inhibition of NHE1 palmitoylation. These results suggest that palmitoylation may regulate NHE1 function and its role in modulating cell migration. Support or Funding Information National Institutes of Health grants DA 031991 (JDF), DA13147 and 5P20‐104360 (RAV), P30‐GM103329 (UND), P20‐GM12345 (UND)