The extracellular Zinc-finger ubiquitin-binding domain of histone Deacetylase 6 enhances podosome formation in neuronal cells.

Neurodegenerative disorders are characterized by progressive synaptic failure, neuronal loss, and the accumulation of pathological protein aggregates. A critical but often overlooked driver of this decline is cytoskeletal dysregulation, which compromises essential cellular functions ranging from intracellular transport to morphological stability. Histone Deacetylase 6 (HDAC6) is a central regulator of these dynamics, yet its role in neurodegeneration remains controversial: while its deacetylase activity is often linked to microtubule instability and toxicity, its ubiquitin-binding functions are essential for aggregate clearance. We have previously demonstrated that the ZnF-UBP domain acts as a direct modulator of cytoskeletal architecture, enhancing the formation of actin-rich migratory structures-such as podosomes and lamellipodia-and promoting neuritic outgrowth. It does this by inducing increased localization of actin remodelling proteins to the podosomes, ultimately conferring enhanced migration potential to cells. This chapter highlights the protocols essential for understanding the therapeutic potential of the HDAC6 Zinc Finger Ubiquitin-Binding Protein (ZnF-UBP) domain, in the context of actin remodelling through podosome structures.