Publication:
Marshall, W. S.; Cozzi, R. R. F.; Spieker, M. 2017. WNK1 and p38-MAPK distribution in ionocytes and accessory cells of euryhaline teleost fish implies ionoregulatory function. Biology Open 6 : 7, 956-966 Melanie Spieker (graduate student from Germany) and research associate Regina Cozzi worked with a new phospho-antibody against WNK1-pT58 and found that the ionocytes stained for this regulatory kinase, as we expected because WNK1 is known to phosphorylate and activate the cotransporter NKCC in salt secreting epithelia. A surprise was that the accessory cells that appear between ionocytes had more WNK1 than did the ionocytes, yet they do not have any NKCC. The implication is that WNK1 in accessory cells has another job to do. Figure Right. Phospho-WNK WNK1-pT58 (Red) is present in ionocytes and accessory cells, while NKCC (Green) is restricted to the ionocytes. There is some colocalization (yellow) of NKCC and WNK1 as expected. The main role of the accessory cells in salt secretion is to provide the cation-permeable paracellular pathway, so WNK1 could have a role to play in maintaining the cation selective claudin pores. We are excited to follow up this project with more work on WNK1 and claudins. |