A Highly Selective, Cell-Permeable Fluorescent Probe for Imaging Histone Deacetylase 6 in Live Cells

Area of Science:

• Biochemistry
• Cell Biology
• Chemical Biology

Background:

• Histone Deacetylase 6 (HDAC6) is vital for cellular functions like cytoskeletal regulation and stress responses.
• HDAC6 dysregulation is implicated in cancers and neurodegenerative diseases, highlighting its therapeutic potential.
• Limited chemical tools for HDAC6 visualization hinder understanding of its dynamic roles in living systems.

Purpose of the Study:

• To develop a novel chemical probe for visualizing HDAC6 in living cells.
• To investigate the dynamic functions of HDAC6 using advanced imaging techniques.

Main Methods:

• Development of the 6SiR-C3-NextA probe, based on the selective HDAC6 inhibitor Nexturastat A and a silicon-rhodamine fluorophore.
• Biochemical and cellular assays to determine probe affinity, selectivity, and cytotoxicity.
• Super-resolution microscopy to visualize endogenous HDAC6 localization and dynamics in various cell lines.

Main Results:

• The 6SiR-C3-NextA probe exhibits high affinity (K_d^app = 21 ± 4 nM) and functional selectivity for HDAC6.
• The probe is cell-permeable, shows low cytotoxicity, and is compatible with super-resolution imaging.
• Successful visualization of endogenous HDAC6, its association with microtubules, and recruitment to stress granules in living cells.

Conclusions:

• 6SiR-C3-NextA is a valuable chemical tool for studying HDAC6 dynamics in real-time.
• The probe enables new insights into HDAC6's role in cellular processes and disease pathogenesis.
• This development opens avenues for exploring HDAC6-targeted therapies.