Systematic Identification of Microtubule Posttranslational Modification "Readers" by Quantitative Proteomics

Area of Science:

• Cell Biology
• Biochemistry
• Proteomics

Background:

• Microtubules are essential polymers involved in cellular processes.
• Microtubule-associated proteins (MAPs) mediate microtubule functions.
• The 'Tubulin Code' hypothesis suggests posttranslational modifications (PTMs) on tubulin act as signals for specific MAPs.

Purpose of the Study:

• To systematically identify MAPs that recognize specific tubulin PTMs in an unbiased manner.
• To develop a robust pipeline for reader identification.
• To provide a complementary in vitro method for generating modified microtubules.

Main Methods:

• Developed a quantitative mass spectrometry-based pipeline.
• Interrogated the microtubule proteome of cells engineered to express specific PTMs.
• Utilized a generic writer enzyme for in vitro production of modified microtubules.

Main Results:

• Successfully identified MAPs that bind to specific tubulin PTMs.
• Demonstrated the pipeline's versatility across different cell types and PTMs.
• Validated an alternative in vitro method for obtaining modified microtubules.

Conclusions:

• The developed pipeline enables systematic and unbiased identification of tubulin PTM readers.
• This work provides a powerful tool to decipher the 'Tubulin Code'.
• Understanding MAP-tubulin PTM interactions is crucial for elucidating microtubule-dependent cellular functions.