First Author | Maruo T | Year | 2018 |
Journal | Mol Cell Neurosci | Volume | 92 |
Pages | 40-49 | PubMed ID | 29969655 |
Mgi Jnum | J:269298 | Mgi Id | MGI:6269821 |
Doi | 10.1016/j.mcn.2018.06.006 | Citation | Maruo T, et al. (2018) Involvement of l-afadin, but not s-afadin, in the formation of puncta adherentia junctions of hippocampal synapses. Mol Cell Neurosci 92:40-49 |
abstractText | A hippocampal mossy fiber synapse has a complex structure in which presynaptic boutons attach to the dendritic trunk by puncta adherentia junctions (PAJs) and wrap multiply-branched spines, forming synaptic junctions. It was previously shown that afadin regulates the formation of the PAJs cooperatively with nectin-1, nectin-3, and N-cadherin. Afadin is a nectin-binding protein with two splice variants, l-afadin and s-afadin: l-afadin has an actin filament-binding domain, whereas s-afadin lacks it. It remains unknown which variant is involved in the formation of the PAJs or how afadin regulates it. We showed here that re-expression of l-afadin, but not s-afadin, in the afadin-deficient cultured hippocampal neurons in which the PAJ-like structure was disrupted, restored this structure as estimated by the accumulation of N-cadherin and alphaNu-catenin. The l-afadin mutant, in which the actin filament-binding domain was deleted, or the l-afadin mutant, in which the alphaNu-catenin-binding domain was deleted, did not restore the PAJ-like structure. These results indicate that l-afadin, but not s-afadin, regulates the formation of the hippocampal synapse PAJ-like structure through the binding to actin filaments and alphaN-catenin. We further found here that l-afadin bound alphaN-catenin, but not gamma-catenin, whereas s-afadin bound gamma-catenin, but hardly alphaN-catenin. These results suggest that the inability of s-afadin to form the hippocampal synapse PAJ-like structure is due to its inability to efficiently bind alphaN-catenin. |