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The Scientific World Journal
Volume 2013, Article ID 156734, 11 pages
http://dx.doi.org/10.1155/2013/156734
Review Article

Genetic Structure and Expression of the Surface Glycoprotein GP82, the Main Adhesin of Trypanosoma cruzi Metacyclic Trypomastigotes

Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Botucatu 862, 04023-062 São Paulo, SP, Brazil

Received 7 December 2012; Accepted 30 December 2012

Academic Editors: S. Amaral Gonçalves da Silva, P. M. L. Dutra, P. Grellier, and J. Martins de Santana

Copyright © 2013 Paulo Roberto Ceridorio Correa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

T. cruzi improves the likelihood of invading or adapting to the host through its capacity to present a large repertoire of surface molecules. The metacyclic stage-specific surface glycoprotein GP82 has been implicated in host cell invasion. GP82 is encoded by multiple genes from the trans-sialidase superfamily. GP82 shows a modular organization, with some variation of N-terminal region flanking a conserved central core where the binding sites to the mammalian cell and gastric mucin are located. The function of GP82 as adhesin in host cell invasion process could expose the protein to an intense conservative and selective pressure. GP82 is a GPI-anchored surface protein, synthesized as a 70 kDa precursor devoid of N-linked sugars. GPI-minus variants accumulate in the ER indicating that GPI anchor acts as a forward transport signal for progressing along the secretory pathway as suggested for T. cruzi mucins. It has been demonstrated that the expression of GP82 is constitutive and may be regulated at post-transcriptional level, for instance, at translational level and/or mRNA stabilization. GP82 mRNAs are mobilized to polysomes and consequently translated, but only in metacyclic trypomastigotes. Analysis of transgenic parasites indicates that the mechanism regulating GP82 expression involves multiple elements in the 3′UTR.