Modulation of kinesin binding by the C-termini of tubulin

• Published in: The EMBO journal Vol. 23; no. 5; pp. 989 - 999
• Main Authors: Skiniotis, Georgios, Cochran, Jared C, Müller, Jens, Mandelkow, Eckhard, Gilbert, Susan P, Hoenger, Andreas
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 10.03.2004; Blackwell Publishing Ltd; Nature Publishing Group
• Subjects: Adenosine diphosphate; Adenosine Diphosphate - metabolism; Adenosine Diphosphate - pharmacology; Adenylyl Imidodiphosphate - metabolism; Adenylyl Imidodiphosphate - pharmacology; Animals; Cattle; cryo-electron microscopy; Dimerization; kinesin; Kinesin - chemistry; Kinesin - metabolism; kinesin neck-linker; Kinetics; Microtubules - metabolism; Models, Molecular; Pliability; Protein Binding - drug effects; Protein Structure, Tertiary; SH3 domain; Trapping; Tubulin - chemistry; Tubulin - genetics; Tubulin - metabolism; tubulin C-terminus
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1038/sj.emboj.7600118

The flexible tubulin C‐terminal tails (CTTs) have recently been implicated in the walking mechanism of dynein and kinesin. To address their role in the case of conventional kinesin, we examined the structure of kinesin–microtubule (MT) complexes before and after CTT cleavage by subtilisin. Our results show that the CTTs directly modulate the motor–tubulin interface and the binding properties of motors. CTT cleavage increases motor binding stability, and kinesin appears to adopt a binding conformation close to the nucleotide‐free configuration under most nucleotide conditions. Moreover, C‐terminal cleavage results in trapping a transient motor–ADP–MT intermediate. Using SH3‐tagged dimeric and monomeric constructs, we could also show that the position of the kinesin neck is not affected by the C‐terminal segments of tubulin. Overall, our study reveals that the tubulin C‐termini define the stability of the MT–kinesin complex in a nucleotide‐dependent manner, and highlights the involvement of tubulin in the regulation of weak and strong kinesin binding states.