<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Nakatani, Fumiki</style></author><author><style face="normal" font="default" size="100%">Morita, Yasu S</style></author><author><style face="normal" font="default" size="100%">Ashida, Hisashi</style></author><author><style face="normal" font="default" size="100%">Nagamune, Kisaburo</style></author><author><style face="normal" font="default" size="100%">Maeda, Yusuke</style></author><author><style face="normal" font="default" size="100%">Kinoshita, Taroh</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Identification of a second catalytically active trans-sialidase in Trypanosoma brucei.</style></title><secondary-title><style face="normal" font="default" size="100%">Biochem Biophys Res Commun</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Biochem. Biophys. Res. Commun.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Sugars</style></keyword><keyword><style  face="normal" font="default" size="100%">Catalysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Membrane</style></keyword><keyword><style  face="normal" font="default" size="100%">Cloning, Molecular</style></keyword><keyword><style  face="normal" font="default" size="100%">Glycoproteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Glycosylphosphatidylinositols</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">N-Acetylneuraminic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Neuraminidase</style></keyword><keyword><style  face="normal" font="default" size="100%">Trypanosoma brucei brucei</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Nov 18</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">415</style></volume><pages><style face="normal" font="default" size="100%">421-5</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The procyclic stage of Trypanosoma brucei is covered by glycosylphosphatidylinositol (GPI)-anchored surface proteins called procyclins. The procyclin GPI anchor contains a side chain of N-acetyllactosamine repeats terminated by sialic acids. Sialic acid modification is mediated by trans-sialidases expressed on the parasite's cell surface. Previous studies suggested the presence of more than one active trans-sialidases, but only one has so far been reported. Here we cloned and examined enzyme activities of four additional trans-sialidase homologs, and show that one of them, Tb927.8.7350, encodes another active trans-sialidase, designated as TbSA C2. In an in vitro assay, TbSA C2 utilized α2-3 sialyllactose as a donor, and produced an α2-3-sialylated product, suggesting that it is an α2-3 trans-sialidase. We suggest that TbSA C2 plays a role in the sialic acid modification of the trypanosome cell surface.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/22040733?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rich, Stephen M</style></author><author><style face="normal" font="default" size="100%">Leendertz, Fabian H</style></author><author><style face="normal" font="default" size="100%">Xu, Guang</style></author><author><style face="normal" font="default" size="100%">LeBreton, Matthew</style></author><author><style face="normal" font="default" size="100%">Djoko, Cyrille F</style></author><author><style face="normal" font="default" size="100%">Aminake, Makoah N</style></author><author><style face="normal" font="default" size="100%">Takang, Eric E</style></author><author><style face="normal" font="default" size="100%">Diffo, Joseph L D</style></author><author><style face="normal" font="default" size="100%">Pike, Brian L</style></author><author><style face="normal" font="default" size="100%">Rosenthal, Benjamin M</style></author><author><style face="normal" font="default" size="100%">Formenty, Pierre</style></author><author><style face="normal" font="default" size="100%">Boesch, Christophe</style></author><author><style face="normal" font="default" size="100%">Ayala, Francisco J</style></author><author><style face="normal" font="default" size="100%">Wolfe, Nathan D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The origin of malignant malaria.</style></title><secondary-title><style face="normal" font="default" size="100%">Proc Natl Acad Sci U S A</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Proc. Natl. Acad. Sci. U.S.A.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Animals</style></keyword><keyword><style  face="normal" font="default" size="100%">Glycoproteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Malaria</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">N-Acetylneuraminic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Pan troglodytes</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">Plasmodium</style></keyword><keyword><style  face="normal" font="default" size="100%">Plasmodium falciparum</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Infections, Animal</style></keyword><keyword><style  face="normal" font="default" size="100%">Protozoan Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Alignment</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009 Sep 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">106</style></volume><pages><style face="normal" font="default" size="100%">14902-7</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Plasmodium falciparum, the causative agent of malignant malaria, is among the most severe human infectious diseases. The closest known relative of P. falciparum is a chimpanzee parasite, Plasmodium reichenowi, of which one single isolate was previously known. The co-speciation hypothesis suggests that both parasites evolved separately from a common ancestor over the last 5-7 million years, in parallel with the divergence of their hosts, the hominin and chimpanzee lineages. Genetic analysis of eight new isolates of P. reichenowi, from wild and wild-born captive chimpanzees in Cameroon and Côte d'Ivoire, shows that P. reichenowi is a geographically widespread and genetically diverse chimpanzee parasite. The genetic lineage comprising the totality of global P. falciparum is fully included within the much broader genetic diversity of P. reichenowi. This finding is inconsistent with the co-speciation hypothesis. Phylogenetic analysis indicates that all extant P. falciparum populations originated from P. reichenowi, likely by a single host transfer, which may have occurred as early as 2-3 million years ago, or as recently as 10,000 years ago. The evolutionary history of this relationship may be explained by two critical genetic mutations. First, inactivation of the CMAH gene in the human lineage rendered human ancestors unable to generate the sialic acid Neu5Gc from its precursor Neu5Ac, and likely made humans resistant to P. reichenowi. More recently, mutations in the dominant invasion receptor EBA 175 in the P. falciparum lineage provided the parasite with preference for the overabundant Neu5Ac precursor, accounting for its extreme human pathogenicity.</style></abstract><issue><style face="normal" font="default" size="100%">35</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/19666593?dopt=Abstract</style></custom1></record></records></xml>