Optogenetic control of the Dab1 signaling pathway

Liang Wang,Jonathan A Cooper

doi:10.1038/srep43760

Abstract

The Reelin-Dab1 signaling pathway regulates development of the mammalian brain, including neuron migrations in various brain regions, as well as learning and memory in adults. Extracellular Reelin binds to cell surface receptors and activates phosphorylation of the intracellular Dab1 protein. Dab1 is required for most effects of Reelin, but Dab1-independent pathways may contribute. Here we developed a single-component, photoactivatable Dab1 (opto-Dab1) by using the blue light-sensitive dimerization/oligomerization property of A. thaliana Cryptochrome 2 (Cry2). Opto-Dab1 can activate downstream signals rapidly, locally, and reversibly upon blue light illumination. The high spatiotemporal resolution of the opto-Dab1 probe also allows us to control membrane protrusion, retraction and ruffling by local illumination in both COS7 cells and in primary neurons. This shows that Dab1 activation is sufficient to orient cell movement in the absence of other signals. Opto-Dab1 may be useful to study the biological functions of the Reelin-Dab1 signaling pathway both in vitro and in vivo.

Highlights

The Reelin-Dab[1] signaling pathway regulates development of the mammalian brain, including neuron migrations in various brain regions, as well as learning and memory in adults
The first requirement is in the intermediate zone (IZ), where Reelin induces the polarization of multi-polar neurons[8]
During central nervous system development, extracellular Reelin binds to the very-low density lipoprotein receptor (VLDLR) and ApoE receptor 2 (ApoER2) receptors on the neuron surface, which activate Src family kinases (SFKs) and phosphorylation of Dab1. pY Dab[1] acts as a key adaptor to recruit and activate immediate downstream effectors near the membrane (Fig. 1a)

Summary

Introduction

The Reelin-Dab[1] signaling pathway regulates development of the mammalian brain, including neuron migrations in various brain regions, as well as learning and memory in adults. The high spatiotemporal resolution of the opto-Dab[1] probe allows us to control membrane protrusion, retraction and ruffling by local illumination in both COS7 cells and in primary neurons. This shows that Dab[1] activation is sufficient to orient cell movement in the absence of other signals. We showed that Dab[1] oligomerization leads to phosphorylation of Dab[1], activates downstream signals, and induces actin cytoskeleton remodeling and membrane protrusion in a variety of cell types, including neurons. The results suggest that Reelin may be a directional signal for neurons in vivo

Methods

Results

Conclusion