OIT3 deficiency impairs uric acid reabsorption in renal tubule.

The oncoprotein induced transcript 3 (OIT3), also named liver-specific zona pellucida domain-containing protein (LZP), has been shown to be expressed in kidney, and was confirmed to interact with the Tamm-Horsfall glycoprotein (THP). However, the function of OIT3 in kidney remains unclear. In this study we found that serum uric acid level of Oit3 null mice was significantly lower than that in wild type controls, whereas the excretion of uric acid in urine increased in the mutant mouse. Significantly, the excretion of THP in urine also increased while renal THP decreased in Oit3 null mice. Our data suggest that OIT3 could maintain urate homeostasis by regulating the excretion and reabsorption of uric acid in renal tubule via cooperating with THP.