Actin-Dependent Alterations of Dendritic Spine Morphology in Shankopathies

Figure 2

Actin in the presynaptic bouton. Actin performs a crucial role in the vesicle trafficking, starting from docking of the vesicle to neurotransmitter release. A special actin binding protein, synapsin, assists actin in this regard. Synapsin can bind with filamentous actin, and together they provide the supportive network for vesicle release. Shank3 can bind with the C-terminal tail of neuroligin 3 and thereby is able to modify the presynaptic signaling via transsynaptic neuroligin-neurexin pathways. Synaptic activity increases the amount of Shank3 in the PSD, which leads to a coordinated increase in presynaptic synapsin. Further, during neuronal development, Shank3 can also be located presynaptically, thereby directly influencing actin dynamics there.