Role of Non-coding RNA in Sculpting Neurons

Abstract

The morphology of neurons, a collective measure of features like the size, number, length, density and branching patterns of dendrites as well as axonal features like length and diameter of the axon, is critical to its function. At a finer level of detail, dendrites bear membranous bulb-like projections on their surfaces called dendritic spines. Dendritic spines are sites of neurotransmitter signalling and undergo activity dependent dynamic changes in shape associated with a regulated rearrangement of the actin cytoskeleton. Kalirin is a Rho-GEF kinase that is involved in the cytoskeletal rearrangements that occur during dendritogenesis and dendrite spine morphologenesis. It is closely associated with the proteins of the post-synaptic density, a structure found at dentritic spines, and through sequential activation of other RhoGTPases, brings about cytoskeletal changes in response to developmental signals and neurotransmitters. We have recently discovered an lncRNA, named Durga, in the zebrafish genome, in close proximity to Kalirin gene, that modulates expression of Kalirin and dendritogenesis. In mammalian genomes, an lncRNA is present at the same position, but with no sequence homology. Here, we provide an overview of dendritogenesis, the molecular basis of dendrite and dendritic spine formation and discuss the invovlement of lncRNA in the process.