TcBDF2 un factor con bromodominio en Trypansoma cruzi

VILLANOVA GV; NARDELLI SC; MAGDALENO A; SILBER AM; SCHENKMAN S; SERRA E

Rosario, Santa Fe, Argentina

Congreso; VIII Congreso de Protozoología y Enfermedades Parasitarias (SAP); 2008

Sociedad Argentina de Protozoología

<!-- /* Font Definitions */ @font-face {font-family:Helvetica; panose-1:2 11 6 4 2 2 2 2 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} @font-face {font-family:Helvetica-Oblique; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt; mso-ascii-font-family:Calibri; mso-hansi-font-family:Calibri;} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The Bromodomain Factor-2 from Trypanosoma cruzi (TcBDF2) is one of the five CDS for bromodomain-containing factors (BDFs) present in the TriTryp´s genome. BD-containing proteins bind acetylated lysine residues and this motif is present in many transcriptional regulators, participating in chromatin structure remodeling and transcription control. We have shown previously that TcBDF2 is localized at the nucleus in all parasite stages and we have seen that it is associated to acetylated histone H4, having preference for K10 and K14 acetylated residues. We have also shown that TcBDF2 expression increased after UV treatment. We analyze TcBDF2 relationship with RNAPolII by immunofluorescence (IFI). It was observed that TcBDF2 co localize with RNAPolII in some regions. To examine TcBDF2 function we attempted expression of a dominant negative TcBDF2. The wild type (wt) TcBDF2 fused to c-myc tag and a C-terminal deleted TcBDF2 (TcBDF2DC) transgenes were expressed from a tetracycline regulated promoter from integrated constructs using pTcINDEX-I vector. The expression of TcBDF2DC caused an important reduction in the growth rate compared with wt or parasites expressing the Red fluorescent protein from pTcINDEX-I-Red (RFP parasites). Nuclear (N) and kinetoplast (K) DNA were visualized with DAPI in individual cells by IFI in TcBDF2DC expressing parasites. Cells were categorized according to the number of K and N. After 48 h post induction we observed cells having abnormal combinations of K and N: 2N1K, 1N0K, 3N1K, 3N2K, 4N1K, 0N1K and 4N2K (n=431), a lower proportion of parasites with 1N2K and 2N2K. Results shown here suggest that TcBDF2 may have a role in T. cruzi biology participating in chromatin structure remodeling processes, although further analysis are needed to know TcBDF2 function.