| First Author | Wang XX | Year | 2021 |
| Journal | J Biol Chem | Pages | 100730 |
| PubMed ID | 33933448 | Mgi Jnum | J:306704 |
| Mgi Id | MGI:6707452 | Doi | 10.1016/j.jbc.2021.100730 |
| Citation | Wang XX, et al. (2021) MRCKbeta links Dasm1 to actin rearrangements to promote dendrite development. J Biol Chem :100730 |
| abstractText | Proper dendrite morphogenesis and synapse formation are essential for neuronal development and function. Dasm1, a member of the immunoglobulin superfamily, is known to promote dendrite outgrowth and excitatory synapse maturation in vitro. However, the in vivo function of Dasm1 in neuronal development and the underlying mechanisms are not well understood. To learn more, Dasm1 knockout mice were constructed and employed to confirm that Dasm1 regulates dendrite arborization and spine formation in vivo. We performed a yeast two-hybrid screen using Dasm1, revealing MRCKbeta as a putative partner; additional lines of evidence confirmed this interaction and identified cytoplasmic proline-rich region (823-947 aa) of Dasm1 and MRCKbeta self-activated kinase domain (CC1, 410-744 aa) as necessary and sufficient for binding. Using co-immunoprecipitation assay, auto-phosphorylation assay and BS3 cross-linking assay, we show that Dasm1 binding triggers a change in MRCKbeta's conformation and subsequent dimerization, resulting in auto-phosphorylation and activation. Activated MRCKbeta in turn phosphorylates a class 2 regulatory myosin light chain (MLC2), which leads to enhanced actin rearrangement, causing the dendrite outgrowth and spine formation observed before. Removal of Dasm1 in mice leads to behavioral abnormalities. Together, these results reveal a crucial molecular pathway mediating cell surface and intracellular signaling communication to regulate actin dynamics and neuronal development in the mammalian brain. |
