Protein Detection and Localization in Plant Cells Using Spot-Tagging.

Area of Science:

• Cell Biology
• Molecular Biology
• Biophysics

Background:

• Fluorescent protein tags are crucial for tracking protein localization but can alter protein function.
• Existing tagging methods often face challenges with protein activity, native localization, and functionality.

Purpose of the Study:

• To introduce and validate the spot-tagging system for protein localization in plant cells.
• To assess the impact of spot-tagging on protein activity and native localization using KIN7.3 as an example.

Main Methods:

• Developed a spot-tagging pipeline for protein labeling in fixed and living plant cells.
• Utilized a 12-amino acid spot-tag recognized by a single-domain nanobody for detection.
• Applied the method to label and localize CENTROMERIC PROTEIN E-RELATED KINESIN 7.3 (KIN7.3).

Main Results:

• Spot-tagging of KIN7.3 did not interfere with its native localization in plant cells.
• The spot-tagging pipeline enabled faster and potentially more accurate KIN7.3 localization compared to traditional methods.
• Identified limitations including functionality only in fixed cells and limited fluorophore availability.

Conclusions:

• Spot-tagging offers a promising alternative to large fluorescent tags for protein localization studies.
• The method overcomes activity perturbations and low photon yields associated with other tagging approaches.
• Further development is needed to address current limitations for broader application.