Control of ENaC ubiquitination

We have explored the mechanisms underlying the ubiquitination of the γ subunit of epithelial Na + channel (ENaC), a process believed to control channel internalization and degradation. We previously reported that the mature, cleaved form of the subunit is selectively ubiquitinated. Here we show that this specificity arises not from the cleavage state of the protein but from its location in the cell. We also show that under some conditions, increased intracellular Na + can stimulate ENaC ubiquitination.