Bicarbonate uptake in the marine macroalga Ulva sp. is inhibited by classical probes of anion exchange by red blood cells
- Cite this article as:
- Drechsler, Z., Sharkia, R., Cabantchik, Z.I. et al. Planta (1993) 191: 34. doi:10.1007/BF00240893
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We demonstrate in this work that HCOinf3sup−uptake in the marine macroalga Ulva sp. features functional resemblances to anion transport mediated by anion exchangers of mammalian cell membranes. The evidence is based on (i) competitive inhibition of photosynthesis by the classical red-blood-cell anion-exchange blockers 4,4′-dinitrostilbene-2,2′-disulfonate and 4-nitro-4′-isothiocyanostilbene-2,2′-disulfonate under conditions where HCOinf3sup−, but not CO2, was the inorganic carbon form taken up; (ii) inhibition of HCOinf3−uptake by pyridoxal phospate, indicating the involvement of lysine residues in the binding/translocation of HCOinf3sup−; and (iii) inhibition of HCOinf3sup−(but not of CO2) uptake by exofacial trypsin treatments, indicating the functional involvement of a plasmalemma protein. It is suggested that HCOinf3sup−uptake mediated by such a putative anion transporter can be a fundamental step in providing inorganic carbon for the CO2-concentrating system of marine marcoalgae in an environment where the HCOinf3sup−concentration is high, but the CO2 concentration and rates of uncatalyzed HCOinf3sup−dehydration are low.
Key wordsAnion exchange(r) (band 3) proteinBicarbonate uptakePhotosynthesisProtein (band 3)Ulva(photosynthesis)