Protein bassoon, also termed zinc finger protein 231, is a core component of the presynaptic cytomatrix. It is a vertebrate-specific active zone scaffolding protein that plays a key role in structural organization and functional regulation of presynaptic release sites. Bassoon may modulate synaptic transmission efficiency by binding to presynaptic P/Q-type voltage-dependent calcium channel (VDCC) complexes and modify the channel function. As one of the most highly phosphorylated synaptic proteins, bassoon can interact with the small ubiquitous adaptor protein 14-3-3 in a phosphorylation-dependent manner, which modulates its anchoring to the presynaptic cytomatrix. Bassoon contains two N-terminal FYVE zinc fingers, a PDZ domain and two C-terminal C2 domains. This family corresponds to the second FYVE domain, which resembles a FYVE-related domain that is structurally similar to the canonical FYVE domains but lacks the three signature sequences: an N-terminal WxxD motif (x for any residue), the central basic R(R/K)HHCRxCG patch, and a C-terminal RVC motif.
Jiyao W et al.(2023). "The conserved domain database in 2023.",