1. Academic Validation
  2. Functional characterization of three novel tissue-specific anion exchangers SLC26A7, -A8, and -A9

Functional characterization of three novel tissue-specific anion exchangers SLC26A7, -A8, and -A9

  • J Biol Chem. 2002 Apr 19;277(16):14246-54. doi: 10.1074/jbc.M111802200.
Hannes Lohi 1 Minna Kujala Siru Makela Eero Lehtonen Marjo Kestila Ulpu Saarialho-Kere Daniel Markovich Juha Kere
Affiliations

Affiliation

  • 1 Department of Medical Genetics, Biomedicum Helsinki and Helsinki University Central Hospital, P. O. Box 63 (Haartmaninkatu 8), 00014 University of Helsinki, Helsinki, Finland.
Abstract

A second distinct family of anion exchangers, SLC26, in addition to the classical SLC4 (or anion exchanger) family, has recently been delineated. Particular interest in this gene family is stimulated by the fact that the SLC26A2, SLC26A3, and SLC26A4 genes have been recognized as the disease genes mutated in diastrophic dysplasia, congenital chloride diarrhea, and Pendred syndrome, respectively. We report the expansion of the SLC26 gene family by characterizing three novel tissue-specific members, named SLC26A7, SLC26A8, and SLC26A9, on chromosomes 8, 6, and 1, respectively. The SLC26A7-A9 proteins are structurally very similar at the amino acid level to the previous family members and show tissue-specific expression in kidney, testis, and lung, respectively. More detailed characterization by immunohistochemistry and/or in situ hybridization localized SLC26A7 to distal segments of nephrons, SLC26A8 to developing spermatocytes, and SLC26A9 to the lumenal side of the bronchiolar and alveolar epithelium of lung. Expression of SLC26A7-A9 proteins in Xenopus oocytes demonstrated chloride, sulfate, and oxalate transport activity, suggesting that they encode functional anion exchangers. The functional characterization of the novel tissue-specific members may provide new insights to anion transport physiology in different parts of body.

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