Takanaga H, Tamai I, Inaba S, Sai Y, Higashida H, Yamamoto H, Tsuji A
Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
Biochem Biophys Res Commun. 1995 Dec 5;217(1):370-7. doi: 10.1006/bbrc.1995.2786.
A cDNA clone which encodes a monocarboxylate transporter (ratMCT1) was isolated from a rat small intestinal cDNA library, which was screened by using full-length MCT1 cDNA of Chinese hamster ovary cells. The ratMCT1 cDNA was sequenced and predicted a protein of 494 amino acids with twelve potential transmembrane domains. The amino acid sequence showed 93.1% and 84.6% identity to the hamster and human monocarboxylate transporters, respectively. When expressed in Xenopus laevis oocytes, the ratMCT1 cRNA caused a significant increase in the uptake of radiolabeled lactic acid. Poly(A)+ RNA transcripts hybridizing to the ratMCT1 cDNA were detected in rat brain, heart, kidney, lung, muscle and brain capillaries. These results indicate that MCT1 contributes to pH-dependent and carrier-mediated transport of monocarboxylic acids in many tissues, not just in the small intestine.
从大鼠小肠cDNA文库中分离出一个编码单羧酸转运体（ratMCT1）的cDNA克隆，该文库是用中国仓鼠卵巢细胞的全长MCT1 cDNA进行筛选的。对ratMCT1 cDNA进行测序，预测其编码一个含有12个潜在跨膜结构域的494个氨基酸的蛋白质。该氨基酸序列与仓鼠和人类单羧酸转运体的同一性分别为93.1%和84.6%。当在非洲爪蟾卵母细胞中表达时，ratMCT1 cRNA导致放射性标记乳酸的摄取显著增加。在大鼠脑、心脏、肾脏、肺、肌肉和脑毛细血管中检测到与ratMCT1 cDNA杂交的聚腺苷酸加尾RNA转录本。这些结果表明，MCT1不仅在小肠中，而且在许多组织中都有助于单羧酸的pH依赖性和载体介导的转运。
