title: Characterization of TcHMGB, a high mobility group B family member protein from Trypanosoma cruzi.
abstract: High mobility group B (HMGB) proteins are highly abundant non-histone chromatin proteins that play important roles in the execution and control of many nuclear functions. Based on homology searches, we identified the coding sequence for the TcHMGB protein, an HMGB family member from Trypanosoma cruzi. TcHMGB has two HMG box domains, similar to mammalian HMGBs, but lacks the typical C-terminal acidic tail. Instead, it contains a 110 amino acid long N-terminal domain. The TcHMGB N-terminal domain is conserved between the TriTryp sequences (70-80% similarity) and seems to be characteristic of kinetoplastid HMGBs. Despite these differences, TcHMGB maintains HMG box architectural functions: we demonstrated that the trypanosomatid HMGB binds distorted DNA structures such as cruciform DNA in gel shift assays. TcHMGB is also able to bend linear DNA as determined by T4 ligase circularization assays, similar to other HMGB family members. Immunofluorescence and western blot assays showed that TcHMGB is a nuclear protein expressed in all life cycle stages. Protein levels, however, seem to vary throughout the life cycle, which may be related to previously described changes in heterochromatin distribution and transcription rates.
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario CP2000, Argentina.
authors.forename: Pamela
authors.initials: P
authors.lastname: Cribb
authors.forename: Marina
authors.initials: M
authors.lastname: Perozzi
authors.forename: Gabriela Vanina
authors.initials: GV
authors.lastname: Villanova
authors.forename: Andrea
authors.initials: A
authors.lastname: Trochine
authors.forename: Esteban
authors.initials: E
authors.lastname: Serra
mesh_terms: D000595:Amino Acid Sequence; D018507:Gene Expression Regulation, Developmental; D006609:High Mobility Group Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014349:Trypanosoma cruzi / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D006609:High Mobility Group Proteins; D015800:Protozoan Proteins