Illuminating microtubule functions with small molecules: past, present and future of fluorescent tubulin-binding probes

Developing tools for the real-time visualization of tubulin, microtubules, and their dynamics is essential for studying key cellular processes such as cell division, migration, and differentiation. In this context, fluorescent small-molecule probes that bind to distinct and specific sites on microtubules have significantly advanced our understanding of tubulin dynamics and functions. In addition, fluorescent probes targeting tubulin have enabled the development of high-throughput screening assays to identify novel anti-tubulin compounds. In this review, we present a comprehensive overview of currently available fluorescent molecules that bind to tubulin, detailing their chemical structures, binding sites, development strategies and relevance to the study of microtubule functions. We also explore future directions in this field and highlight key fluorescent probes that are still lacking. Developing these tools would enable the investigation of tubulin's diverse cellular roles in even greater depth and support the advancement of tubulin-targeted therapeutics.