pYtags - our in vivo biosensors for receptor tyrosine kinases - in all their beauty on the cover of Cell Reports! Read more here: www.cell.com/cell-reports...

Excited to share that our work building in vivo biosensors for receptor tyrosine kinases (pYtags!) is now out www.cell.com/cell-reports...

I’ll be starting my undergrad-powered lab this summer at Claremont McKenna College and I’m super excited to continuing exploring new signaling biology with pYtags. If you are interested in tagging your favorite RTK (in flies or in other model systems), please reach out!

Our data is consistent with a new conceptual model for terminal patterning where a local domain of Torso activity, tuned by negative feedback, produces a long-range gradient of ERK. Check out the paper to learn more!

First, Torso activity decreased over developmental time while ERK activity was sustained at a high level. This led us to the discovery of negative feedback from the ERK pathway regulating Torso’s phosphorylation state.

We then asked what we could learn about Torso by comparing Torso activity with downstream ERK activity. Two things surprised us, highlighting that we can’t always accurately infer receptor activity from downstream signaling.

And pYtags didn’t just work for Torso! We also made pYtags for EGFR and FGFR/Btl, and those worked just as well. The pYtag strategy is so powerful because it is generalizable to any RTK of interest.

We were particularly interested in Torso, the RTK controlling terminal ERK signaling at the poles of the fly embryo. I tagged Torso with the pYtag and saw gorgeous signal at the poles just where we expected it! pYtags work in embryos!

pYtags use an exceptionally specific and orthogonal pTyr / SH2 binding pair (ITAM + ZtSH2) to recruit a fluorescently tagged protein to phosphorylated RTKs.

The Toettcher lab recently developed a new class of biosensors for receptor tyrosine kinases (RTKs) called pYtags. They work beautifully in mammalian cell culture. But could pYtags be used to measure endogenous RTK activity in embryos?

elifesciences.org/articles/82863

Have you ever wanted to *see* receptor activity in embryos? If so, our new preprint is for you! In it, we showcase a new live-cell biosensor for visualizing receptor tyrosine kinase activity in living embryos – pYtags!

www.biorxiv.org/content/10.1...