Oxalate in renal stone disease: the terminal metabolite that just won't go away.

The incidence of calcium oxalate nephrolithiasis in the US has been increasing throughout the past three decades. Biopsy studies show that both calcium oxalate nephrolithiasis and nephrocalcinosis probably occur by different mechanisms in different subsets of patients. Before more-effective medical therapies can be developed for these conditions, we must understand the mechanisms governing the transport and excretion of oxalate and the interactions of the ion in general and renal physiology.

Stimulatory and Inhibitory Functions of the R Domain on CFTR Chloride Channel.

CFTR is a chloride channel whose gating process involves coordinated interactions among the regulatory (R) domain and the nucleotide-binding folds (NBFs). Protein kinase A phosphorylation of serine residues renders the R domain from inhibitory to stimulatory and enables ATP binding and hydrolysis at the NBFs, which in turn control opening and closing of the chloride channel.