Ammonia exposure increases the expression of Na + :K + :2Cl − cotransporter 1a in the gills of the giant mudskipper, Periophthalmodon schlosseri

摘要: The giant mudskipper, Periophthalmodon schlosseri, is an obligate air-breathing teleost that can actively excrete ammonia against high concentrations of environmental ammonia. This study aimed to clone and sequence the Na + :K :2Cl − cotransporter 1 (nkcc1) from gills P. determine effects exposure on its mRNA expression protein abundance after pre-acclimation slightly brackish water (salinity 3; SBW) for 2 weeks. complete coding cDNA sequences nkcc1a consisted 3453 bp, 1151 amino acid with estimated molecular mass 125.4 kDa. Exposure 75 mmol l−1 NH4Cl in SBW had no effect nkcc1a. However, western blotting revealed a significant increase multiple T4-immunoreactive bands 170–250 kDa schlosseri exposed Furthermore, immunofluorescence microscopy demonstrated colocalization increased Na+/K+-ATPase (Nka) α-subunit basolateral membrane certain ionocytes ammonia-exposed fish. As Nkcc1 known have localization, it be concluded led glycosylated Nkcc1, masses which were reduced upon enzymatic deglycosylation, schlosseri. dependency post-transcriptional post-translational regulation branchial would facilitate prompt responses changes condition. NH4 + replace K+, could probably enter through Nkcc1a during active excretion, but influx Na+, 2Cl− alter transmembrane Na+ gradient. Consequently, also result activity Nka decreased affinity so as maintain intracellular K+ homeostasis reported elsewhere.