Canonical histone H2Ba dimerizes with H2A.X in an opposite genomic localization to H2A.Z/H2B.Z dimers in Toxoplasma gondii

SILVINA S. BOGADO; MARIA C. DALMASSO; AGUSTINA GANUZA; KAMI KIM; WILLIAM J. SULLIVAN JR.; SERGIO O. ANGEL; LAURA VANAGAS

Mar del Plata

Congreso; X Congreso de protozoología y Enfermedades Infecciosas; 2014

Sociedad Argentina de Protozoología (SAP)

Histone H2Ba of Toxoplasma gondii was expressed as recombinant protein (rH2Ba) and used to generate antibody in rabbit that is highly specific. Antibody recognizing rH2Ba detects a single band in tachyzoite lysate of the expected molecular weight (12 kDa). By indirect immunofluorescence (IFA) in in vitro grown tachyzoites and bradyzoites, the signal was detected only in the parasite nucleus. The nucleosome composition of H2Ba was determined through co-immunoprecipitation assays. H2Ba was detected in the same immunocomplex as H2A.X, but not with H2A.Z. Through chromatin immunoprecipitation (ChIP) assays and QPCR, it was observed that H2Ba is located at promoters of inactive genes and silent regions, accompanying H2A.X and opposed to H2B.Z.