Significance of taurine transporter (TauT) in homeostasis and its layers of regulation (Review)

Abstract

Taurine (2‑aminoethanesulfonic acid) contributes to homeostasis, mainly through its antioxidant and osmoregulatory properties. Taurine's influx and efflux are mainly mediated through the ubiquitous expression of the sodium/chloride‑dependent taurine transporter, located on the plasma membrane. The significance of the taurine transporter has been shown in various organ malfunctions in taurine‑transporter‑null mice. The taurine transporter differentially responds to various cellular stimuli including ionic environment, electrochemical charge, and pH changes. The renal system has been used as a model to evaluate the factors that significantly determine the regulation of taurine transporter regulation.

Keywords: taurine transporter; regulation; taurine deficient conditions.

Figure 1.

A representative scheme for the regulation of TauT transporter. The regulation of TauT transporter activity involves phosphorylation/dephosphorylation/oxidation of TauT or a putative regulator of TauT by protein kinases A and C (PKA, PKC), casein kinase 2 (CK2), hyperosmolarity and reactive oxygen species (ROS). Long-term regulation of TauT involves modulation of gene transcription by protein kinases (mTOR), transcription factors (WT1, cJun, c-Myb) and tonicity-responsive enhancer binding protein (TonEBP) or cell death signaling (p53 transcription factor).