Title:	Estudos biofísicos e in vivo de moléculas ligantes de nucleossomo
Authors:	Teles, Kaian Amorim
Orientador(es)::	Santos, Guilherme Martins
Assunto::	Peptídeos Nucleossomo Cromatina Lipídios Separação de fase
Issue Date:	24-Jun-2020
Data de defesa::	15-Jun-2020
Citation:	TELES, Kaian Amorim. Estudos biofísicos e in vivo de moléculas ligantes de nucleossomo. 2020. 113 f., il. Tese (Doutorado em Patologia Molecular)—Universidade de Brasília, Brasília, 2020.
Abstract:	The modulation of chromatin is known to be orchestrated by Nucleosome Binding Molecules (NBMs), which would act on the nucleosome surface to modulate chromatin architecture. Herein, we evaluated if Nucleosome Binding Peptides (NBPeps) would be able to occupy the nucleosome surface directly, thereby modulating chromatin status and influencing phenotypic outcomes. To understand how the nucleosome structure is affected by NBPeps, we performed biochemical assays indicating that NBPeps present differential actions on the nucleosome structure despite binding to similar target regions on the nucleosome. Cell-based assays showed that NBPeps are uptake by HeLa cells by an active mechanism and have selective toxicity for HeLa cells when compared to CCD10595K cells. Using Zebrafish models we demonstrated that NBPeps penetrated different tissues, showing specific effects on cell physiology and phenotypic outcome, altering the development of zebrafish embryos, inhibiting the development of melanocytes, changing hatching patterns and inducing death at a small rate. Moreover, analysis in adult zebrafish showed that NBPeps can reach the nuclear environment of erythrocytes in vivo. We concluded that NBPeps present specific phenotypic outcomes in zebrafish embryos despite having a similar binding sites. Taken together, our data suggests that NBPeps might have important therapeutic implications. Herein, we also reviewed the impacts of lipids on the nuclear environment, discussing the potential role of nucleosome as a reservoir of lipids in the nucleus and, also emphasizing the lipids as a modulator of chromatin architecture. Finally, we investigated the capacity of a NBPep (H4pep) in creating phase separation in vitro. Droplet assay shows that H4pep requires DNA to crate phase separation, also that the complex DNA:H4pep at high concentrations can change phase creating a gel-liquid phase separation. Salt resistance assay shows that H4pep creates phase separation at a physiological concentration of NaCl. The relevance biological relevance of this data is yet to be determined.
metadata.dc.description.unidade:	Faculdade de Medicina (FM)
Description:	Tese (doutorado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Patologia Molecular, 2020.
metadata.dc.description.ppg:	Programa de Pós-Graduação em Patologia Molecular
Licença::	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Appears in Collections:	Teses, dissertações e produtos pós-doutorado

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