Physiological significance of the taurine transporter and taurine biosynthetic enzymes in 3T3‐L1 adipocytes
Physiological significance of the taurine transporter and taurine biosynthetic enzymes in 3T3‐L1 adipocytes
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DOI：
10.1002/biof.552210183
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发表时间：
2004
期刊：
影响因子：
6
通讯作者：
Masakazu Takasaki;H. Satsu;M. Shimizu
中科院分区：
文献类型：
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作者：
Masakazu Takasaki;H. Satsu;M. Shimizu
牛磺酸的细胞内水平由牛磺酸转运蛋白（TAUT）和Met和Cys的内源性合成维持。在本研究中，我们研究了3 T3-L1脂肪细胞中TAUT和半胱氨酸双加氧酶（CDO）（牛磺酸生物合成的主要酶之一）的调节。高渗可上调TAUT活性、TAUT和CDO mRNA的表达。相反，TAUT活性、TAUT和CDO mRNA的表达在富含牛磺酸的条件下下调。此外，还表明TAUT活性的上调是由表达的TAUT数量增加引起的，而不是由TAUT亲和力的变化引起的。另一方面，牛磺酸诱导的TAUT活性下调不仅是由于表达的TAUT数量减少，而且还由于其亲和力降低。这些结果表明，小鼠TAUT和CDO在高渗和富含牛磺酸的条件下协同调节。
The intracellular level of taurine is maintained both by the taurine transporter (TAUT) and by endogenous synthesis from Met and Cys. We investigated in the present study the regulation of TAUT and of cysteine dioxygenase (CDO), one of the major taurine biosynthetic enzymes, in 3T3‐L1 adipocytes. The TAUT activity, expression of TAUT and CDO mRNA were up‐regulated by hypertonicity. In contrast, the TAUT activity, expression of TAUT and CDO mRNA were down‐regulated by taurine‐rich conditions. Furthermore, it was indicated that the up‐regulation of TAUT activity resulted from the increased number of expressed TAUT, and not by the change in affinity of TAUT. On the other hand, the taurine‐induced down‐regulation of TAUT activity resulted not only from a decrease in the number of expressed TAUT but also from a decrease in their affinity. These results suggest that murine TAUT and CDO were cooperatively regulated in response to hypertonicity and taurine‐rich conditions.