PFKFB4 control of AKT signaling is essential for premigratory and migratory neural crest formation

Abstract

Neural crest (NC) specification comprises an early phase, initiating immature NC progenitors formation at neural plate stage, and a later phase at neural fold stage, resulting in a functional premigratory NC that is able to delaminate and migrate. We found that the NC gene regulatory network triggers upregulation of pfkfb4 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4) during this late specification phase. As shown in previous studies, PFKFB4 controls AKT signaling in gastrulas and glycolysis rate in adult cells. Here, we focus on PFKFB4 function in NC during and after neurulation, using time-controlled or hypomorph depletions in vivo We find that PFKFB4 is essential both for specification of functional premigratory NC and for its migration. PFKFB4-depleted embryos fail to activate n-cadherin and late NC specifiers, and exhibit severe migration defects resulting in craniofacial defects. AKT signaling mediates PFKFB4 function in NC late specification, whereas both AKT signaling and glycolysis regulate migration. These findings highlight novel and essential roles of PFKFB4 activity in later stages of NC development that are wired into the NC gene regulatory network.

Keywords: 6-Phosphofructo-2-kinase/fructose-2; 6-bisphosphatase; AKT; Glycolysis; Migration; Neural crest; Neural plate border; PFKFB; Xenopus laevis embryo.