We report here that intracellular pH (pH(i)) in cleavage-stage human embryos (2-8-cell) is regulated by at least two mechanisms: the HCO(3)(-)/Cl(-) exchanger (relieves alkalosis) and the Na(+)/H(+) antiporter (relieves acidosis). The mean pH(i) of cleavage-stage embryos was 7.12 +/- 0.008 (n = 199) with little variation between different stages. Embryos demonstrated robust recovery from alkalo...

The anion exchanger phosphocellulose and the cation exchanger triethylaminoethyl cellulose were used to immobilize cells of the fungus Aureobasidium pullulans ATCC 201253 and the adsorbed cells were subsequently investigated for their ability to produce the polysaccharide pullulan using batch fermentation. The cells adsorbed on the triethylaminoethyl cellulose at pH 7.5 produced higher pullulan...

Distal renal tubular acidosis caused by missense mutations in kidney isoform of anion exchanger 1 (kAE1/SLC4A1), the basolateral membrane Cl-/HCO3- exchanger of renal alpha-intercalated cells, has been extensively investigated in heterologous expression systems but rarely in human kidneys. The preferential apical localization of distal renal tubular acidosis (dRTA)-associated kAE1 mutants R901X...

The molecular identity of the apical HCO3(-)-secreting transporter in gastric mucous cells remains unknown despite its essential role in preventing injury and ulcer by gastric acid. Here we report the identification of a Cl-/HCO3- exchanger that is located on apical membranes of gastric surface epithelial cells. RT-PCR studies of mouse gastrointestinal tract mRNAs demonstrated that this transpo...

Cell migration is crucial for processes such as immune defense, wound healing, or the formation of tumor metastases. Typically, migrating cells are polarized within the plane of movement with lamellipodium and cell body representing the front and rear of the cell, respectively. Here, we address the question of whether this polarization also extends to the distribution of ion transporters such a...

A thin liquid layer covers the lungs of air-breathing vertebrates. Active ion transport processes via the pulmonary epithelial cells regulate the maintenance of this layer. This study focuses on basolateral Cl(-) uptake mechanisms in native lungs of Xenopus laevis and the involvement of the Na(+)/K(+)/2 Cl(-) cotransporter (NKCC) and HCO(3)(-)/Cl(-) anion exchanger (AE), in particular. Western ...

Boron is an important micronutrient in plants and animals. The role of boron in living systems includes coordinated regulation of gene expression, growth and proliferation of higher plants and animals. There are several well-defined genes associated with boron transportation and tolerance in plants and these genes show close homology with human anion exchanger genes. Mutation of these gen...