Confocal microscopy is fun! The image above is immunocytochemistry of "with no lysine kinase" phospho antibody WNK1 pT58 WNK (red) and CFTR (green) in the apical membrane of ionocytes in the opercular epithelium of the killifish Fundulus heteroclitus, acclimated to seawater. Some cells have WNK across the whole cytosol, but the ionocyte with CFTR in the apical membrane (ring shape) has only small amounts of phosphorylated WNK where the accessory cells insert cation-selective junctions. The accessory cells have large amounts of phosphorylated WNK1 which may regulate the claudin proteins that form the cation-selective ion pores between cells that allow sodium to be secreted into seawater.
Publication: Marshall, W.S., Watters, K.D., Hovdestad, L.R., Cozzi, R.R.F., *Katoh, F. CFTR Cl- channel functional regulation by phosphorylation of focal adhesion kinase at tyrosine 407 in osmosensitive ion transporting mitochondria rich cells of euryhaline killifish. J. exp. Biol. 212:2365-2377 (2009)
Publication: Marshall, W.S., Watters, K.D., Hovdestad, L.R., Cozzi, R.R.F., *Katoh, F. CFTR Cl- channel functional regulation by phosphorylation of focal adhesion kinase at tyrosine 407 in osmosensitive ion transporting mitochondria rich cells of euryhaline killifish. J. exp. Biol. 212:2365-2377 (2009)