Chemical Probe for Imaging of Polo-like Kinase 4 and Centrioles

Polo-like kinase (Plk4) is a serine/threonine-proteinkinase thatis essential for biogenesis of the centriole organelle and is enrichedat centrioles. Herein, we introduce Cen-TCO, a chemical probe basedon the Plk4 inhibitor centrinone, to image Plk4 and centrioles inlive or fixed cultured human cells. Specifically, we established abio-orthogonal two-step labeling system that enables the Cen-TCO-mediatedimagingof Plk4 by STED super-resolution microscopy. Such direct labelingof Plk4 results in an increased resolution in STED imaging comparedwith using anti-Plk4 antibodies, underlining the importance of directlabeling strategies for super-resolution microscopy. We anticipatethat Cen-TCO will become an important tool for investigating the biologyof Plk4 and of centrioles.

Automated summary

Polo-like kinase (Plk4) is crucial for the biogenesis of centrioles, and a chemical probe called Cen-TCO based on the Plk4 inhibitor centrinone is introduced to visualize Plk4 and centrioles in live or fixed human cells. A bio-orthogonal two-step labeling system is established, allowing the direct labeling of Plk4 for STED super-resolution microscopy. Direct labeling of Plk4 improves the resolution of STED imaging compared to using anti-Plk4 antibodies, highlighting the significance of direct labeling strategies for super-resolution microscopy. Cen-TCO is expected to be an important tool for investigating the biology of Plk4 and centrioles.