CCDC84

Model summary

A human centrosome- and spindle-associated scaffold that uses multivalent protein binding to organize assemblies controlling centrosome duplication and mitotic spindle function. By concentrating at cytoplasmic cytoskeletal hubs, it assembles and stabilizes complexes that restrain centrosome biogenesis while coupling centrosomal and spindle components to proteostasis pathways. This coordination helps balance microtubule nucleation with selective turnover, thereby tuning both assembly and degradation of cell-cycle machinery at the microtubule-organizing center and spindle apparatus.

Predicted Gene Ontology terms

1. 01

   I begin with the InterPro architecture: a single, continuous family signature IPR028015 (CCDC84-like family) spanning residues 5–329.

   A solitary, full-length family domain of this kind typically encodes a coiled-coil–rich scaffold that mediates multivalent protein–protein interactions rather than enzymatic chemistry. The absence of catalytic subdomains and the breadth of the family signature together argue that this polypeptide functions primarily through binding and assembly of larger complexes, which causally supports a molecular function centered on GO:0005515 protein binding.

2. 02

   A coiled-coil scaffold localized to centrosomal and spindle structures naturally governs cell-cycle–linked assemblies.

   The CCDC84-like family architecture predisposes the protein to dock onto pericentriolar and spindle-associated modules, where it can tune duplication and segregation machinery. This binding-driven control provides a mechanistic route to the biological processes observed: by assembling and stabilizing complexes that govern centriole biogenesis and turnover, the protein enacts GO:0010826 negative regulation of centrosome duplication. Its scaffolding role also positions it to modulate ubiquitin–proteasome pathways that remodel centrosomal and spindle components, aligning with GO:0042176 regulation of protein catabolic process.

3. 03

   The cellular geography follows directly from this architecture and function.

   A soluble, coiled-coil scaffold without transmembrane segments is expected to concentrate at cytoplasmic, cytoskeletal hubs. Its operational sites are the microtubule-organizing center and the spindle apparatus, which map to GO:0005813 centrosome and, by extension, the adjacent cytoplasm and cytoskeleton. This localization explains how the protein can coordinate both assembly and turnover of centrosomal and spindle constituents during mitosis.

4. 04

   Mechanistically, I hypothesize that the CCDC84-like scaffold nucleates assemblies that restrain centrosome duplication by sequestering or positioning regulatory factors and by coupling them to proteostasis machinery.

   At the centrosome and spindle poles, it likely binds pericentriolar matrix and spindle organizers to balance microtubule nucleation with selective degradation. Candidate partners include core duplication and spindle regulators (such as PLK4, CEP152, CEP192, STIL, TUBG1, NUMA1, and TPX2) and ubiquitin–proteasome adaptors that tune centrosome component turnover. Through these interactions, the scaffold can both suppress excess duplication and choreograph timely catabolism of assembly factors to ensure faithful mitotic progression.