Kinetochore- and microtubule-binding protein that plays a key role in spindle assembly (PubMed:24462186, PubMed:24462187, PubMed:26388440). ZNF207/BuGZ is mainly composed of disordered low-complexity regions and undergoes phase transition or coacervation to form temperature-dependent liquid droplets. Coacervation promotes microtubule bundling and concentrates tubulin, promoting microtubule polymerization and assembly of spindle and spindle matrix by concentrating its building blocks (PubMed:26388440). Also acts as a regulator of mitotic chromosome alignment by mediating the stability and kinetochore loading of BUB3 (PubMed:24462186, PubMed:24462187). Mechanisms by which BUB3 is protected are unclear: according to a first report, ZNF207/BuGZ may act by blocking ubiquitination and proteasomal degradation of BUB3 (PubMed:24462186). According to another report, the stabilization is independent of the proteasome (PubMed:24462187). Interacts (via GLEBS region) with BUB3. Localizes primarily to the nucleus in interphase, concentrates at kinetochores prior to nuclear envelope breakdown and during early prometaphase, and disappears from kinetochores upon microtubule-binding. Experimental confirmation may be lacking for some isoforms. Ubiquitous. The GLEBS region mediates interaction with BUB3 (PubMed:24462186, PubMed:24462187). The microtubule-binding region is required for efficient loading of BUB3 onto kinetochores and proper mitosis. Mainly composed of disordered low-complexity regions outside of the C2H2-type zinc fingers. Coacervation depends on hydrophobic and aromatic Phe and Tyr in the disordered low-complexity region, that may promote coacervation by forming intermolecular hydrophobic interactions.