Announcing our new PA biosensor, PILS-Nir1 – seen here in HeLa cells during PLC activation #lipidtime #phospholipids

Read the OA paper in JCB

Since this occurs because the biosensor is outcompeting the native AKT1 molecules, Victoria tried expressing biosensors at lower levels where we resolve single biosensor molecules (shown in magenta). Hey presto! No inhibition:

Now Victoria expressed the most popular PIP3 biosensor - the PH domain from the very same AKT1 protein (pink). The biosensor recruits very nicely with EGF, reporting PIP3 increases - but completely kills native AKT1 recruitment, as you see here:

Morgan tagged endogenous AKT1 with NeonGreen. Expression is low enough that you see single molecules at the cell surface in TIRF, which are recruited by PIP3 when the cell is stimulated with EGF: