Primary sequence, tissue specificity and mRNA expression of the Na⁺,K⁺ -ATPase β1 subunit in the European eel (Anguilla anguilla)

The entire amino acid coding sequence of the Na+,K+-ATPase β1 isoform was cloned from the gill of the European eel ( Anguilla anguilla ) by a PCR based method. The amino acid sequence translated from the nucleotide sequence shared 61.4 and 56.2% homology respectively with previously published Na+,K+-ATPase β1 isoform sequences from the clawed toad ( Xenopus laevis ) and the ray ( Torpedo californica ) an elasmobranch fish. The size of the Na+,K+-ATPase β1 mRNA transcript in eel tissues was demonstrated to be 2.35 Kb. Detectable levels of Na+,K+-ATPase β1 mRNA were found at some level in all tissues except liver and cardiac muscle. The level of branchial Na+,K+-ATPase β1 mRNA was observed to increase after the adaptation of fresh water eels to normal or double concentration sea water.