Limits...
Genomic organization and expression profile of the mucin-associated surface protein (masp) family of the human pathogen Trypanosoma cruzi.

Bartholomeu DC, Cerqueira GC, Leão AC, daRocha WD, Pais FS, Macedo C, Djikeng A, Teixeira SM, El-Sayed NM - Nucleic Acids Res. (2009)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. daniella@icb.ufmg.br

ABSTRACT
A novel large multigene family was recently identified in the human pathogen Trypanosoma cruzi, causative agent of Chagas disease, and corresponds to approximately 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.

Show MeSH

Related in: MedlinePlus

MASP protein features. (A) MASP protein sequence. All 771 MASP proteins containing both N- and C-terminal conserved regions were aligned using ClustalW (6). A consensus sequence was generated and a percentage identity score was computed for each position across the entire sequence. The conserved N- and C-terminal domains encoding the predicted signal peptide and predicted GPI anchor addition site are boxed. The amino acids surrounding the putative signal peptide addition site are underlined, while those surrounding the predicted GPI-addition site are italicized and underlined. The arrows indicate threonine residues close to the mature C-terminal region. (B) Multidimensional scaling plot representing the matrix of distance among the sequences derived from the N- (right panel) and C-terminal (left panel) conserved domains from MASP (yellow), TcMUCI (dark gray), TcMUCII (orange), TcMUCIII (pink), TcSMUGS (light gray), TcSMUGL (red) and SAP genes (turquoise).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2691823&req=5

Figure 4: MASP protein features. (A) MASP protein sequence. All 771 MASP proteins containing both N- and C-terminal conserved regions were aligned using ClustalW (6). A consensus sequence was generated and a percentage identity score was computed for each position across the entire sequence. The conserved N- and C-terminal domains encoding the predicted signal peptide and predicted GPI anchor addition site are boxed. The amino acids surrounding the putative signal peptide addition site are underlined, while those surrounding the predicted GPI-addition site are italicized and underlined. The arrows indicate threonine residues close to the mature C-terminal region. (B) Multidimensional scaling plot representing the matrix of distance among the sequences derived from the N- (right panel) and C-terminal (left panel) conserved domains from MASP (yellow), TcMUCI (dark gray), TcMUCII (orange), TcMUCIII (pink), TcSMUGS (light gray), TcSMUGL (red) and SAP genes (turquoise).

Mentions: An alignment of the amino-acid sequences of 771 full-length MASP proteins revealed highly conserved N- and C-terminal domains that were predicted to encode a signal peptide and a GPI-anchor addition site, respectively (Figure 4A), suggesting a surface location in the parasite. The central region varies both in sequence (Figure 4A) and in length (ranging from 176 to 645 amino-acid residues) (Supplementary Figure S2) and often contains repetitive motifs.Figure 4.


Genomic organization and expression profile of the mucin-associated surface protein (masp) family of the human pathogen Trypanosoma cruzi.

Bartholomeu DC, Cerqueira GC, Leão AC, daRocha WD, Pais FS, Macedo C, Djikeng A, Teixeira SM, El-Sayed NM - Nucleic Acids Res. (2009)

MASP protein features. (A) MASP protein sequence. All 771 MASP proteins containing both N- and C-terminal conserved regions were aligned using ClustalW (6). A consensus sequence was generated and a percentage identity score was computed for each position across the entire sequence. The conserved N- and C-terminal domains encoding the predicted signal peptide and predicted GPI anchor addition site are boxed. The amino acids surrounding the putative signal peptide addition site are underlined, while those surrounding the predicted GPI-addition site are italicized and underlined. The arrows indicate threonine residues close to the mature C-terminal region. (B) Multidimensional scaling plot representing the matrix of distance among the sequences derived from the N- (right panel) and C-terminal (left panel) conserved domains from MASP (yellow), TcMUCI (dark gray), TcMUCII (orange), TcMUCIII (pink), TcSMUGS (light gray), TcSMUGL (red) and SAP genes (turquoise).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2691823&req=5

Figure 4: MASP protein features. (A) MASP protein sequence. All 771 MASP proteins containing both N- and C-terminal conserved regions were aligned using ClustalW (6). A consensus sequence was generated and a percentage identity score was computed for each position across the entire sequence. The conserved N- and C-terminal domains encoding the predicted signal peptide and predicted GPI anchor addition site are boxed. The amino acids surrounding the putative signal peptide addition site are underlined, while those surrounding the predicted GPI-addition site are italicized and underlined. The arrows indicate threonine residues close to the mature C-terminal region. (B) Multidimensional scaling plot representing the matrix of distance among the sequences derived from the N- (right panel) and C-terminal (left panel) conserved domains from MASP (yellow), TcMUCI (dark gray), TcMUCII (orange), TcMUCIII (pink), TcSMUGS (light gray), TcSMUGL (red) and SAP genes (turquoise).
Mentions: An alignment of the amino-acid sequences of 771 full-length MASP proteins revealed highly conserved N- and C-terminal domains that were predicted to encode a signal peptide and a GPI-anchor addition site, respectively (Figure 4A), suggesting a surface location in the parasite. The central region varies both in sequence (Figure 4A) and in length (ranging from 176 to 645 amino-acid residues) (Supplementary Figure S2) and often contains repetitive motifs.Figure 4.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. daniella@icb.ufmg.br

ABSTRACT
A novel large multigene family was recently identified in the human pathogen Trypanosoma cruzi, causative agent of Chagas disease, and corresponds to approximately 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.

Show MeSH
Related in: MedlinePlus