Molecular diversity of the Trypanosoma cruzi TcSMUG family of mucin genes and proteins

IVANA URBAN; LUCÍA BOIANI SANTURIO; AGUSTINA CHIDICHIMO; HAI YU; XI CHEN; JUAN MUCCI; FERNÁN AGÜERO; CARLOS A. BUSCAGLIA

BIOCHEMICAL JOURNAL

PORTLAND PRESS LTD

Año: 2011 p. 303 - 313

0264-6021

The surface of the protozoan Trypanosoma cruzi is covered by a dense coat of mucin-type glycoconjugates, which make a pivotal contribution to parasite protection and host immune evasion. Their importance is further underscored by the presence of >1,000 mucin-like genes in the parasite genome. In the present study we demonstrate that one such group of genes, termed TcSMUG L, codes for previously unrecognized mucin-type glycoconjugates anchored to and secreted from the surface of insect-dwelling epimastigotes. These features are supported by the in vivo tracing and characterization of endogenous TcSMUG L products and recombinant tagged molecules expressed by transfected parasites. Besides displaying substantial homology to TcSMUG S products, which provide the scaffold for the major Gp35/50 mucins also present in insect-dwelling stages, TcSMUG L products display unique structural and functional features, including being completely refractory to sialylation by parasite trans-sialidases.Although quantitative real time-PCR and gene sequencing analyses indicate a high degree of genomic conservation across the T. cruzi species, TcSMUG L product expression and processing is quite variable among different parasite isolates.