Bassoon (1) is a 420 kDa protein that is a localized at the presynaptic nerve terminals and is believed to play a role
in the structural and functional organization of the
synaptic vesicle cycle. Bassoon is predicted to contain
two double-zinc fingers, three coiled-coil regions, and
two polyglutamine domains. The polyglutamine domains
in the C-terminus are of interest, since it is known that
for some human proteins, such as Huntington, abnormal
amplification of this region can cause late-onset
neurodegeneration. Bassoon is concentrated at sites
opposite to postsynaptic densities in synaptic terminals
and in cultured neurons, it is found to co-localize with
GABA (A) and glutamate (GluR1) receptors.