Premium
Molecular and immunological characterization of Na + /H + antiporter (NHE3) in the gills of a marine teleost ( Myoxocephalus octodecemspinosus )
Author(s) -
Claiborne James B.,
Edwards Susan,
Kratochvilova Hana,
Diamanduros Andrew,
Lanier Curtis,
Hyndman Kelly,
Evans David,
Cutler Christopher,
Foster Makesha
Publication year - 2008
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.22.1_supplement.1239.8
Subject(s) - gill , microbiology and biotechnology , biology , sodium–hydrogen antiporter , messenger rna , apical membrane , intracellular ph , pendrin , acid–base homeostasis , in situ hybridization , chemistry , biochemistry , intracellular , transporter , sodium , gene , membrane , fish <actinopterygii> , organic chemistry , fishery
The marine long horn sculpin compensates for metabolic acidosis by excretion of net acid equivalents across the branchial epithelium. Transfer of H + is dependent on external Na + and can be inhibited by amiloride. We have evidence that at least four orthologs of mammalian Na + /H + exchangers are expressed in the gills (NHE1–3, 8). In this study, we have cloned a full open reading frame for gill NHE3. mRNA (Northerns; 4.3–4.8 kb) and protein expression (Westerns; ~104 kd) band sizes were similar to mammalian NHE3. In situ hybridization with anti‐sense probe recognized cells at the base of the lamellae and in the interlamellar space. This location was confirmed with florescent immunohistochemistry using species specific antibodies. Strong apical NHE3 signal was detected in gill cells within the interlamellar region. Na + /K + ‐ATPase was colocalized to these cells as well. Sculpin specific antibodies against H + ‐ATPase detected cytoplasmic expression of this protein in a separate subpopulation of gill cells. Paralleling in vivo net H + efflux, NHE3 mRNA signal increased two hours after an infused acid load while apical NHE3 protein expression was detected in both control and acid loaded animals. Thus it appears that an NHE3 ortholog is coexpressed in Na + /K + ‐ATPase rich gill cells and likely contributes to H + excretion for acid‐base regulation. Supported by NSF‐IBN‐0616187 to JBC.