Genetic disruption of bassoon in two mutant mouse lines causes divergent retinal phenotypes

Abstract

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Bassoon controls synaptic vesicle pools via regulation of presynaptic phosphorylation and cAMP homeostasis

“…We have shown previously that Bsn organises presynaptic voltage-gated calcium channels in neuronal cell types (Frank et al, 2010;Hallermann et al, 2010;Ryl et al, 2021). In cortical and hippocampal synapses, it is required for specific recruitment of Cav2.1 (P/Q-type channels) channels to the release sites and consequently, relatively more Cav2.2 (N-type) channels are present at synapses in the absence of Bsn (Davydova et al, 2014).…”

“…Therefore, the Cav2.1 and Cav1.3 channels, respectively, are less abundant in corticohippocampal glutamatergic synapses or cochlear and retinal ribbon synapses of Bsn mutants (Frank et al, 2010;Davydova et al, 2014;Babai et al, 2019;Ryl et al, 2021).…”

“…Investigations of mouse strains expressing shortened or null Bsn alleles detected reduced RRP and slower vesicular replenishment in glutamatergic synapses of cultured hippocampal neurons, cerebellar mossy fibers, photoreceptors, cochlear inner hair cells, and auditory nerve fibers in the absence of functional Bsn (Altrock et al, 2003;Khimich et al, 2005;Frank et al, 2010;Hallermann et al, 2010;Jing et al, 2013;Mendoza Schulz et al, 2014;Babai et al, 2019;Babai et al, 2020;Ryl et al, 2021).…”

Bassoon controls synaptic vesicle release via regulation of presynaptic phosphorylation and cAMP

“…Bsn was shown to coordinate the recruitment of specific presynaptic voltage‐gated calcium channels to the active zone via its interaction with RIM‐binding proteins (Davydova et al , 2014 ). Therefore, the Cav2.1 and Cav1.3 channels, respectively, are less abundant in cortico‐hippocampal glutamatergic synapses or cochlear and retinal ribbon synapses of Bsn mutants (Frank et al , 2010 ; Davydova et al , 2014 ; Babai et al , 2019 ; Ryl et al , 2021 ). Investigations of mouse strains expressing shortened or null Bsn alleles detected reduced RRP and slower vesicular replenishment in glutamatergic synapses of cultured hippocampal neurons, cerebellar mossy fibres, photoreceptors, cochlear inner hair cells and auditory nerve fibres (Altrock et al , 2003 ; Khimich et al , 2005 ; Frank et al , 2010 ; Hallermann et al , 2010 ; Jing et al , 2013 ; Mendoza Schulz et al , 2014 ; Babai et al , 2019 , 2021 ; Ryl et al , 2021 ).…”

“…Therefore, the Cav2.1 and Cav1.3 channels, respectively, are less abundant in cortico‐hippocampal glutamatergic synapses or cochlear and retinal ribbon synapses of Bsn mutants (Frank et al , 2010 ; Davydova et al , 2014 ; Babai et al , 2019 ; Ryl et al , 2021 ). Investigations of mouse strains expressing shortened or null Bsn alleles detected reduced RRP and slower vesicular replenishment in glutamatergic synapses of cultured hippocampal neurons, cerebellar mossy fibres, photoreceptors, cochlear inner hair cells and auditory nerve fibres (Altrock et al , 2003 ; Khimich et al , 2005 ; Frank et al , 2010 ; Hallermann et al , 2010 ; Jing et al , 2013 ; Mendoza Schulz et al , 2014 ; Babai et al , 2019 , 2021 ; Ryl et al , 2021 ). The morphological analyses also pointed towards a role of Bsn (and its paralogue Piccolo) in the SV clustering and RRP regulation (Altrock et al , 2003 ; Mukherjee et al , 2010 ; Mendoza Schulz et al , 2014 ; Ackermann et al , 2019 ; Hoffmann‐Conaway et al , 2020 ).…”