Fructose transporter in human spermatozoa and small intestine is GLUT5.
Fructose transporter in human spermatozoa and small intestine is GLUT5.
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DOI：
10.1016/s0021-9258(18)42067-4
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发表时间：
1992-07
期刊：
影响因子：
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通讯作者：
C. Burant;J. Takeda;É. Brot-Laroche;G. Bell;N. Davidson
中科院分区：
文献类型：
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作者：
C. Burant;J. Takeda;É. Brot-Laroche;G. Bell;N. Davidson
我们最近报道了葡萄糖转运蛋白异构体GLUT5在人小肠肠细胞的刷状边界膜上表达（Davidson, n.o, Hausman, a.m.l, Ifkovits, c.a, bus, j.b, Gould, g.w, Burant, c.f, and Bell, g.i.(1992)）。中国生物医学工程学报（英文版）。为了确定其在糖转运中的作用，我们在非洲爪蟾卵母细胞中表达了人GLUT5，并测定了其底物特异性和动力学特性。抑制研究表明，GLUT5对果糖转运具有选择性，其Km为6 mM。此外，GLUT5的果糖转运不受细胞松弛素B（一种促进性葡萄糖转运蛋白的竞争性抑制剂）的抑制。RNA和蛋白印迹研究表明，人类睾丸和精子中存在高水平的GLUT5 mRNA和蛋白，免疫细胞化学研究将GLUT5定位于成熟精子和精子的质膜上。GLUT5的生化特性和组织分布与该蛋白作为果糖转运蛋白的生理作用一致。
We recently reported that the glucose transporter isoform, GLUT5, is expressed on the brush border membrane of human small intestinal enterocytes (Davidson, N. O., Hausman, A. M. L., Ifkovits, C. A., Buse, J. B., Gould, G. W., Burant, C. F., and Bell, G. I. (1992) Am. J. Physiol. 262, C795-C800). To define its role in sugar transport, human GLUT5 was expressed in Xenopus oocytes and its substrate specificity and kinetic properties determined. GLUT5 exhibits selectivity for fructose transport, as determined by inhibition studies, with a Km of 6 mM. In addition, fructose transport by GLUT5 is not inhibited by cytochalasin B, a competitive inhibitor of facilitative glucose transporters. RNA and protein blotting studies showed the presence of high levels of GLUT5 mRNA and protein in human testis and spermatozoa, and immunocytochemical studies localize GLUT5 to the plasma membrane of mature spermatids and spermatozoa. The biochemical properties and tissue distribution of GLUT5 are consistent with a physiological role for this protein as a fructose transporter.