Actin-Dependent Alterations of Dendritic Spine Morphology in Shankopathies

Figure 1

Formation of filamentous actin. Monomeric G actin can exchange GDP with GTP, depending on the energy status of the cell. Such GTP bound actin proteins are more stable and can form oligomers using weak noncovalent interactions. Such oligomers serve as nucleus for further oligomerization. Actin binding proteins (ABPs) can accelerate this process. Once oligomerized, the structure has polarity for adding new activated monomers. The (+) end can elongate the filamentous structure via adding new monomers, whereas on the (−) end the GTP bound actin is converted to GDP bound stage and dissociates from the filament. Such actin tread milling is a key component in regulation of cellular structure, morphogenesis, and activity.