title: Organization and expression of the gene encoding an immunodominant repetitive antigen associated to the cytoskeleton of Trypanosoma cruzi.
abstract: We have studied the genomic organization and expression of the gene encoding a high molecular mass (300 kDa) repetitive antigen associated with the cytoskeleton of Trypanosoma cruzi. Protease digestion of the native protein, restriction analysis of genomic DNA and sequencing of genomic and cDNA clones indicated that most of the protein is built up by tandemly arranged, nearly identical repeats of 68 amino acids. The gene size was estimated to be approx. 9.4 kb based on the sizes of the transcript and the native protein. The nucleotide sequence conservation among the repeats indicates that selective sequence homogenization, presumably through gene conversion, maintained the amino-acid sequence conservation. Two duplicated allelic forms of this gene were mapped in fragments of about 20 kb. In some strains an additional allele was located in a fragment of 9.4 kb. Our results suggest that this repetitive antigen is a structural protein which could be involved in the attachment of the flagellum to the cell body.
authors.affiliation: Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, São Paulo, Brazil.
authors.forename: P C
authors.initials: PC
authors.lastname: Cotrim
authors.forename: G
authors.initials: G
authors.lastname: Paranhos-Baccala
authors.forename: M R
authors.initials: MR
authors.lastname: Santos
authors.forename: C
authors.initials: C
authors.lastname: Mortensen
authors.forename: M I
authors.initials: MI
authors.lastname: Cano
authors.forename: M
authors.initials: M
authors.lastname: Jolivet
authors.forename: M E
authors.initials: ME
authors.lastname: Camargo
authors.forename: R A
authors.initials: RA
authors.lastname: Mortara
authors.forename: J F
authors.initials: JF
authors.lastname: Da Silveira
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000235:genetics; D003599:Cytoskeleton / Q000737:chemistry*; D005786:Gene Expression Regulation; D017125:Genes, Protozoan / Q000235:genetics*; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D016053:RNA, Protozoan / Q000032:analysis; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D014349:Trypanosoma cruzi / Q000235:genetics* / Q000276:immunology
chemical_list: D000953:Antigens, Protozoan; D003598:Cytoskeletal Proteins; D015800:Protozoan Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan