Characterization of a cDNA clone encoding the carboxy-terminal domain of a 90-kilodalton surface antigen of Trypanosoma cruzi metacyclic trypomastigotes.
We have cloned and sequenced a cDNA for a metacyclic trypomastigote-specific glycoprotein with a molecular mass of 90 kDa, termed MTS-gp90. By immunoblotting, antibodies to the MTS-gp90 recombinant protein reacted exclusively with a 90-kDa antigen of metacyclic trypomastigotes. The insert of the MTS-gp90 cDNA clone strongly hybridized with a single 3.0-kb mRNA of metacyclic forms, whereas the hybridization signal with epimastigote mRNA was weak and those with RNAs from other developmental stages were negative, indicating that transcription of the MTS-gp90 gene is developmentally regulated. A series of experiments showed that the MTS-gp90 gene is present in multiple copies in the Trypanosoma cruzi genome, arranged in a nontandem manner, and that there are at least 40 copies of the gene per haploid genome. Sequence analysis of recombinant MTS-gp90 revealed 40 to 60% identity at the amino acid level with members of a family of mammalian stage-specific, 85-kDa surface antigens of T. cruzi. However, there are considerable differences in the amino acid compositions outside the homology region.
Franco
F R
FR
Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, São Paulo, Brazil.
Paranhos-Bacallà
G S
GS
Yamauchi
L M
LM
Yoshida
N
N
da Silveira
J F
JF
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D005796:Genes; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D014349:Trypanosoma cruzi / Q000235:genetics* / Q000276:immunology
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D015800:Protozoan Proteins; D012333:RNA, Messenger