Chikamori Minoru, Fukushima Kazutaka
Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Chuo-ku, Chiba 260-8673, Japan.
Fungal Genet Biol. 2005 Jul;42(7):646-55. doi: 10.1016/j.fgb.2005.04.004.
We carried out a screen for Cryptococcus neoformans genes involved in resistance to copper ion toxicity and identified a new hexose transporter (Hxt) gene, HXT1. Hxt1 consists of 520 amino acids and functions to transport hexoses such as glucose. Although Hxt1 conferred copper resistance to Saccharomyces cerevisiae, disruption of the HXT1 gene showed that Hxt1 is not necessary for copper resistance. In virulence tests, an hxt1 mutant strain showed 12% less phenoloxidase activity than the wild-type strain, and no difference in the ability to form melanin was identified. In addition, the hxt1 mutant strain showed virulence similar to that of the wild-type strain in experiments with Caenorhabditis elegans. However, the hxt1 mutant strain generated larger capsules than were generated by the wild-type strain. Thus, Hxt1 appears to be involved in capsule formation.
我们对新型隐球菌中参与抗铜离子毒性的基因进行了筛选，鉴定出一个新的己糖转运蛋白（Hxt）基因HXT1。Hxt1由520个氨基酸组成，其功能是转运葡萄糖等己糖。虽然Hxt1赋予酿酒酵母抗铜性，但HXT1基因的破坏表明Hxt1并非抗铜所必需。在毒力测试中，hxt1突变株的酚氧化酶活性比野生型菌株低12%，且未发现形成黑色素的能力有差异。此外，在秀丽隐杆线虫实验中，hxt1突变株表现出与野生型菌株相似的毒力。然而，hxt1突变株产生的荚膜比野生型菌株更大。因此，Hxt1似乎参与荚膜形成。
