title: The Calcineurin A homologue from Trypanosoma cruzi lacks two important regulatory domains.
abstract: A novel protein from the parasite Trypanosoma cruzi homologous to calcineurin (serine-threonine phosphatase 2B) was identified and characterized. The Calcineurin A gene is present as a single copy gene per haploid genome and encodes a protein of 43 kDa that is expressed in all major developmental stages of T. cruzi. Surprisingly, it is mainly localized in the cell nucleus, in sharp contrast with its mammalian counterpart. The T. cruzi calcineurin A protein presents the three invariants motifs characteristic of the PPP serine-threonine phosphatase superfamily. However, out of the four domains typically present in all calcineurin described to date, the T. cruzi calcineurin A possess only two domains: the catalytic and the calcineurin B binding domain. Sequence similarity searches in the T. cruzi, Trypanosoma brucei and Leishmania major genomes revealed that only L. major presents a gene encoding a putative protein containing the four domains. On the other hand, the T. cruzi Calcineurin B subunit showed a conserved structure, and a reasonable level of similarity over the entire length with calcineurin B proteins from other organisms. Interaction between Calcineurin A and Calcineurin B was analyzed by yeast Two-Hybrid and GST pull-down assays.
authors.affiliation: Instituto de Investigaciones Biotecnológicas, Universidad Nacional de General San Martín, CONICET, Buenos Aires, Argentina.
authors.forename: Valeria Ruiz
authors.initials: VR
authors.lastname: Moreno
authors.forename: Fernán
authors.initials: F
authors.lastname: Agüero
authors.forename: Valeria
authors.initials: V
authors.lastname: Tekiel
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Sánchez
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D019703:Calcineurin / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000235:genetics*; D020798:Two-Hybrid System Techniques
chemical_list: D016053:RNA, Protozoan; D011994:Recombinant Proteins; D019703:Calcineurin