# Organotellurium Probes Enable One-step Single-cell Analysis of Post-translational Modification

## TL;DR

A new method using organotellurium probes allows single-cell analysis of protein prenylation, a key modification linked to disease and aging.

## Contribution

A one-step method using tellurium-containing isoprenoid analogues enables direct quantification of prenylation in single cells via mass cytometry.

## Key findings

- Tellurium probes allow single-step detection of prenylation in various cell lines.
- Prenylation levels are altered in autophagy-deficient L6 cells, relevant to aging.
- Chemical proteomics identifies prenylation targets via oxidation-controlled reactions.

## Abstract

Protein prenylation is a widespread post-translational
modification
(PTM) that regulates membrane association and signaling; dysregulation
of this process leads to a variety of diseases. Metabolic labeling
with probes containing bioorthogonal functionality has revolutionized
the study of many protein modifications, including prenylation. However,
that approach requires two steps, including metabolic incorporation
and subsequent bioorthogonal reaction to install chemical reporters.
Here, we present the development and application of tellurium-containing
isoprenoid analogues that can be incorporated through a single enzymatic
step and enable the direct quantification of prenylation at the single-cell
level by mass cytometry. This robust methodology was examined in a
variety of cell lines and used to show that prenylation levels are
perturbed in autophagy-deficient L6 cells, a model for certain features
of aging. Modification of tellurium-labeled proteins through the oxidation-controlled
strain-promoted tellurophene-alkyne cycloaddition reaction also enabled
the identification of prenylation targets by chemical proteomics.
This methodology bridges proteomic and multiplexed single-cell analyses,
opening up promising avenues for exploring a variety of post-translational
modifications.