ISSN:
1432-2048
Keywords:
Anion exchange(r) (band 3) protein
;
Bicarbonate uptake
;
Photosynthesis
;
Protein (band 3)
;
Ulva(photosynthesis)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We demonstrate in this work that HCO inf3 sup− 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 HCO inf3 sup− , but not CO2, was the inorganic carbon form taken up; (ii) inhibition of HCO inf3 − uptake by pyridoxal phospate, indicating the involvement of lysine residues in the binding/translocation of HCO inf3 sup− ; and (iii) inhibition of HCO inf3 sup− (but not of CO2) uptake by exofacial trypsin treatments, indicating the functional involvement of a plasmalemma protein. It is suggested that HCO inf3 sup− 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 HCO inf3 sup− concentration is high, but the CO2 concentration and rates of uncatalyzed HCO inf3 sup− dehydration are low.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00240893
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