Acetylation-Specific Interference by Anti-Histone H3K9ac Intrabody Results in Precise Modulation of Gene Expression

Abstract

Among Histone post-translational modifications (PTMs), lysine acetylation plays a pivotal role in the epigenetic regulation of gene expression, mediated by chromatin modifying enzymes. Due to their activity in physiology and pathology, several chemical compounds have been developed to inhibit the function of these proteins. However, the pleiotropy of these classes of proteins represents a weakness of epigenetic drugs. Ideally, a new generation of epigenetic drugs should target with molecular precision individual acetylated lysines on the target protein. We exploit a PTM-directed interference, based on an intrabody (scFv-58F) that selectively binds acetylated lysine 9 of histone H3 (H3K9ac), to test the hypothesis that targeting H3K9ac yields more specific effects than inhibiting the corresponding HAT enzyme that installs that PTM. In yeast scFv-58F modulates, gene expression in a more specific way, compared to two well-established HAT inhibitors. This PTM-specific interference modulated expression of genes involved in ribosome biogenesis and function. In mammalian cells, the scFv-58F induces exclusive changes in the H3K9ac-dependent expression of specific genes. These results suggest the H3K9ac-specific intrabody as the founder of a new class of molecules to directly target histone PTMs, inverting the paradigm from inhibiting the writer enzyme to acting on the PTM.

Small Tweaks, Major Changes: Post-Translational Modifications That Occur within M2 Macrophages in the Tumor Microenvironment

“…Few studies have explored the possibility of directly targeting the proteins in which PTMs occur, proving that the effect of selectively targeting a PTM could be better than directly targeting the entire kinase in charge of a PTM. A good example is provided by the study of Lisi S et al [ 91 ]. The authors precisely interfered with the acetylated lysine 9 of histone H3 (H3K9ac) rather than with the entire histone acetylase transferase (HAT), and the interferential effect turned out to be more specific compared with the HAT inhibitors.…”

Studying of protein-DNA interactions in the cells of immune system using chromatin immunoprecipitation and chromatin immunocleavage

“…Описанная выше система контроля экспрессии генов позволяет быстро и точно регулировать клеточный ответ, что представляется особенно важным в случае иммунной системы, так как нарушения регуляции экспрессии генов в клетках иммунной системы могут приводить к повреждению тканей и органов, например при таких заболеваниях и состояниях, как сепсис, аутоиммунные и аутовоспалительные заболевания, реакции гиперчувствительности, первичные иммунодефициты и т. д. Таким образом, информация о взаимодействии белков с ДНК важна как для расшифровки фундаментальных механизмов функционирования иммунной системы, так и для понимания патогенеза конкретных заболеваний, связанных с нарушением этих механизмов, а следовательно, и для разработки новых методов лечения [11]. Хотя методы исследования взаимодействий белков с ДНК довольно трудоемки, они с успехом применяются во многих научных лабораториях.…”