Glycolytic enzyme-tubulin interactions: Role of tubulin carboxy terminals

Tubulin and microtubules were modified with the protease, subtilisin. The modification reduced the length of α‐or β‐tubulin by cleaving a peptide fragment from the C‐terminals. Generation of α′β′‐tubulin, which is cleaved at both the α‐ and β‐subunit terminals, and αβ′‐tubulin, which is cleaved at the β′‐subunit C‐terminal, have already been reported. In this work an isotype, α′β‐tubulin, was produced. The three modified tubulin isotypes were compared for their ability to interact with glycolytic enzymes. Cleavage of α led to a poorer interaction when tested via affinity chromatography. Tubulin also inhibits the activity of aldolase and glyceraldehyde 3‐phosphate dehydrogenase. When the α‐subunit C‐terminal was intact, inhibition was greatest. These results imply that the C‐terminal of the tubulin α‐subunit is subunit is responsible for interactions with glycolytic enzymes.