Direct Spatiotemporal Visualization of Tyrosine Phosphorylation Dynamics in Live Cells by Biocompatible Aggregation-Induced Emission Peptide

X. Zhang, Y. Zhao, G. Zou, X-J Liang
National Center for Nanoscience and Technology, CN

Keywords: nanotechnology, peptides, live cell imaging, aggregation-induced emission, phosphorylation

Summary:

In summary, we developed a tetraphenylethene (TPE) tagged phosphopeptide as a probe to monitor the dynamic change of tyrosine dephosphorylation and phosphorylation in live cells. This TPE tagged phophopeptide was soluble in aqueous solution and cell-membrane permeable. Upon dephosphorylation by phosphatases inside the cell, the TPE tagged peptide assembled into nano aggregate and displayed strong aggregation-induced emission. The dephosphorylation-induced aggregation was instantaneous and the resulted fluorescent nano particles were not dissipating or self-quenching like many small organic fluorescent probes, herein, this TPE-tagged probe gave precise temporal and spatial resolution. The process was reversible, re-phosphorylation of the TPE-tagged peptide dissemble the nano aggregate and caused the AIE-induced fluorescence to fade away. The appearance and disappearance of fluorescence were closely correlated with tyrosine phosphorylation and dephosphorylation. Using this probe, two distinct phosphorylation/dephosphorylation patterns for osteoblasts and breast cancer cells were revealed, which were not reported before.