Nucleic Acids Research Advance Access originally published online on March 31, 2009
Nucleic Acids Research 2009 37(10):3407-3417; doi:10.1093/nar/gkp172
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nucleic Acids Research, 2009, Vol. 37, No. 10 3407-3417
© 2009 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Genomics |
Genomic organization and expression profile of the mucin-associated surface protein (masp) family of the human pathogen Trypanosoma cruzi
1Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil, 2Department of Cell Biology and Molecular Genetics, 3Center for Bioinformatics and Computational Biology, 4Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA, 5Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil and 6J. Craig Venter Institute, Rockville, MD 20850, USA
*To whom correspondence should be addressed. Tel: +1 301 4052999; Fax: +1 301 838 0208; Email: elsayed{at}umd.edu
Correspondence may also be addressed to Daniella C. Bartholomeu. Tel: +5531 3409 2825; Fax: +5531 3409 2970; Email: daniella{at}icb.ufmg.br
Received January 9, 2009. Revised February 27, 2009. Accepted March 2, 2009.
A novel large multigene family was recently identified in the human pathogen Trypanosoma cruzi, causative agent of Chagas disease, and corresponds to 
6% of the parasite diploid genome. The predicted gene products, mucin-associated surface proteins (MASPs), are characterized by highly conserved N- and C-terminal domains and a strikingly variable and repetitive central region. We report here an analysis of the genomic organization and expression profile of masp genes. Masps are not randomly distributed throughout the genome but instead are clustered with genes encoding mucin and other surface protein families. Masp transcripts vary in size, are preferentially expressed during the trypomastigote stage and contain highly conserved 5' and 3' untranslated regions. A sequence analysis of a trypomastigote cDNA library reveals the expression of multiple masp variants with a bias towards a particular masp subgroup. Immunofluorescence assays using antibodies generated against a MASP peptide reveals that the expression of particular MASPs at the cell membrane is limited to subsets of the parasite population. Western blots of phosphatidylinositol-specific phospholipase C (PI-PLC)-treated parasites suggest that MASP may be GPI-anchored and shed into the medium culture, thus contributing to the large repertoire of parasite polypeptides that are exposed to the host immune system.