PT  - JOURNAL ARTICLE
AU  - Joseph Masseya
AU  - Yida Liua
AU  - Omar Alvarengaa
AU  - Teresa Saeza
AU  - Matthew Schmerera
AU  - Aryeh Warmflasha
TI  - Synergy with TGFß ligands switches WNT pathway dynamics from transient to sustained during human pluripotent cell differentiation
AID  - 10.1101/406306
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 406306
4099  - http://biorxiv.org/content/early/2018/09/22/406306.short
4100  - http://biorxiv.org/content/early/2018/09/22/406306.full
AB  - WNT/ß-catenin signaling is crucial to all stages of life. It controls early morphogenetic events in embryos, maintains stem-cell niches in adults, and is disregulated in many types of cancer. Despite its ubiquity, little is known about the dynamics of signal transduction or whether it varies across contexts. Here we probe the dynamics of signaling by monitoring nuclear accumulation of ß-catenin, the primary transducer of canonical WNT signals, using quantitative live-cell imaging. We show that ß-catenin signaling responds adaptively to constant WNT signaling in pluripotent stem cells, and that these dynamics become sustained upon differentiation. Varying dynamics were also observed in the response to WNT in commonly used mammalian cell-lines. Signal attenuation in pluripotent cells is controlled by both intra- and extra-cellular negative regulation of WNT signaling. TGFß-superfamily ligands Activin and BMP, which coordinate with WNT signaling to pattern the gastrula, increase the ß-catenin response in a manner independent of their ability to induce new WNT-ligand production. Our results reveal how variables external to the pathway, including differentiation status and crosstalk with other pathways, dramatically alter WNT/ß-catenin dynamics.