一组以前不知道的糖运输蛋白已被识别出来――最初是在植物中, 但由于同源蛋白明显广泛分布,所以它们也在动物中被识别出。
在植物中,这些SWEET受体相应于那些人们长期寻找的、向花蜜、种子和花粉发育供应葡萄糖的运输蛋白。这些运输蛋白中的其中一些被病原体利用来为复制提供糖。后生动物同源蛋白也调控葡萄糖运输,并且还可能涉及糖从小肠、肝脏、附睾和乳腺细胞中的流出。(生物谷Bioon.com)
生物谷推荐英文摘要:
Nature doi:10.1038/nature09606
Sugar transporters for intercellular exchange and nutrition of pathogens
Li-Qing Chen,Bi-Huei Hou,Sylvie Lalonde,Hitomi Takanaga,Mara L. Hartung,Xiao-Qing Qu,Woei-Jiun Guo,Jung-Gun Kim,William Underwood,Bhavna Chaudhuri,Diane Chermak,Ginny Antony,Frank F. White,Shauna C. Somerville,Mary Beth Mudgett" Wolf B. Frommerwfrommer@carnegiescience.edu
Sugar efflux transporters are essential for the maintenance of animal blood glucose levels, plant nectar production, and plant seed and pollen development. Despite broad biological importance, the identity of sugar efflux transporters has remained elusive. Using optical glucose sensors, we identified a new class of sugar transporters, named SWEETs, and show that at least six out of seventeen Arabidopsis, two out of over twenty rice and two out of seven homologues in Caenorhabditis elegans, and the single copy human protein, mediate glucose transport. Arabidopsis SWEET8 is essential for pollen viability, and the rice homologues SWEET11 and SWEET14 are specifically exploited by bacterial pathogens for virulence by means of direct binding of a bacterial effector to the SWEET promoter. Bacterial symbionts and fungal and bacterial pathogens induce the expression of different SWEET genes, indicating that the sugar efflux function of SWEET transporters is probably targeted by pathogens and symbionts for nutritional gain. The metazoan homologues may be involved in sugar efflux from intestinal, liver, epididymis and mammary cells.