Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Biol Chem. 2011 Jul 29;286(30):26888-99. doi: 10.1074/jbc.M111.262162. Epub 2011 May 23.
Cryptococcal meningoencephalitis is an AIDS-defining illness caused by the opportunistic pathogen Cryptococcus neoformans. This organism possesses an elaborate polysaccharide capsule that is unique among pathogenic fungi, and the glycobiology of C. neoformans has been a focus of research in the field. The capsule and other cellular glycans and glycoconjugates have been described, but the machinery responsible for their synthesis remains largely unexplored. We recently discovered Xpt1p, an enzyme with the unexpected activity of generating a xylose-phosphate-mannose linkage. We now demonstrate that this novel activity is conserved throughout the C. neoformans species complex, localized to the Golgi apparatus, and functions in the O-glycosylation of proteins. We also present the first survey of O-glycans from C. neoformans.
隐球菌性脑膜脑炎是一种艾滋病定义性疾病，由机会性病原体新生隐球菌引起。这种生物体具有独特的多糖荚膜，这在致病真菌中是独一无二的，新生隐球菌的糖生物学一直是该领域研究的重点。已经描述了荚膜和其他细胞糖和糖缀合物，但负责它们合成的机制在很大程度上仍未被探索。我们最近发现了 Xpt1p，这是一种具有产生木糖-磷酸-甘露糖键的意外活性的酶。我们现在证明，这种新的活性在整个新生隐球菌种复合体中是保守的，定位于高尔基体，并在蛋白质的 O-糖基化中发挥作用。我们还展示了对新生隐球菌 O-聚糖的首次调查。
