The microtubule-associated histone methyltransferase SET8, facilitated by transcription factor LSF, methylates α-tubulin.
Hang Gyeong ChinPierre-Olivier EsteveCristian RuseJiyoung LeeScott E SchausSriharsa PradhanUlla HansenPublished in: The Journal of biological chemistry (2020)
Microtubules are cytoskeletal structures critical for mitosis, cell motility, and protein and organelle transport and are a validated target for anticancer drugs. However, how tubulins are regulated and recruited to support these distinct cellular processes is incompletely understood. Posttranslational modifications of tubulins are proposed to regulate microtubule function and dynamics. Although many of these modifications have been investigated, only one prior study reports tubulin methylation and an enzyme responsible for this methylation. Here we used in vitro radiolabeling, MS, and immunoblotting approaches to monitor protein methylation and immunoprecipitation, immunofluorescence, and pulldown approaches to measure protein-protein interactions. We demonstrate that N-lysine methyltransferase 5A (KMT5A or SET8/PR-Set7), which methylates lysine 20 in histone H4, bound α-tubulin and methylated it at a specific lysine residue, Lys311 Furthermore, late SV40 factor (LSF)/CP2, a known transcription factor, bound both α-tubulin and SET8 and enhanced SET8-mediated α-tubulin methylation in vitro In addition, we found that the ability of LSF to facilitate this methylation is countered by factor quinolinone inhibitor 1 (FQI1), a specific small-molecule inhibitor of LSF. These findings suggest the general model that microtubule-associated proteins, including transcription factors, recruit or stimulate protein-modifying enzymes to target tubulins. Moreover, our results point to dual functions for SET8 and LSF not only in chromatin regulation but also in cytoskeletal modification.
Keyphrases
- transcription factor
- genome wide
- dna methylation
- small molecule
- amino acid
- protein protein
- dna binding
- gene expression
- emergency department
- mass spectrometry
- binding protein
- stem cells
- cell therapy
- dna damage
- escherichia coli
- single cell
- high resolution
- bone marrow
- staphylococcus aureus
- pseudomonas aeruginosa
- cystic fibrosis