Microtubule binding proteins CLIP-170, EB1, and p150Glued form distinct plus-end complexes.
Microtubule plus-end proteins CLIP-170 and EB1 dynamically track the tips of growing microtubules in vivo. Here we examine the association of these proteins with microtubules in vitro. CLIP-170 binds tubulin dimers and co-assembles into growing microtubules. EB1 binds tubulin dimers more weakly, so no co-assembly is observed. However, EB1 binds to CLIP-170, and forms a co-complex with CLIP-170 and tubulin that is recruited to growing microtubule plus ends. The interaction between CLIP-170 and EB1 is competitively inhibited by the related CAP-Gly protein p150Glued, which also localizes to microtubule plus ends in vivo. Based on these observations, we propose a model in which the formation of distinct plus-end complexes may differentially affect microtubule dynamics in vivo.
Ligon
Lee A
LA
Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Shelly
Spencer S
SS
Tokito
Mariko K
MK
Holzbaur
Erika L F
EL
D000818:Animals; D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D046912:Multiprotein Complexes; D009363:Neoplasm Proteins / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins; D014404:Tubulin / Q000494:pharmacology
D000072159:Dynactin Complex; C405804:EB1 microtubule binding proteins; D008869:Microtubule-Associated Proteins; D046912:Multiprotein Complexes; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D014404:Tubulin; C076744:cytoplasmic linker protein 170