MCAK associates with EB1

Abstract

The microtubule (MT)-associated protein EB1 localizes to and promotes growth at MT plus ends. The MT depolymerizing kinesin MCAK has also been reported to track growing MT plus ends. Here, we confirm that human MCAK colocalizes with EB1 at growing MT ends when expressed as a GFP fusion protein in transfected cells. We show that MCAK associates with the C-terminus of EB1 and EB3 but much less efficiently with RP1. EB1 associates with the N-terminal localization and regulatory domain in MCAK but not with the motor domain of the protein. The interaction is competitive with the binding of other EB1 ligands and does not require MTs. Knockdown of EB1 expression using siRNA impaired the ability of GFP-MCAK to localize to MT tips in transfected cells. We propose that MCAK is targeted to growing MT ends by EB1, that MCAK is held in an inactive conformation when associated with EB1 and that this could provide the basis for a mechanism that facilitates rapid switching between phases of MT growth and depolymerization.

Cell cycle-regulated expression and subcellular localization of a kinesin-8 member human KIF18B

“…5 and 6B), KIF18B is suggested to perform following functions. First, it may be involved in transporting target molecules (or organelles) through interaction with interphase MTs like many other kinesins and references therein) or in regulating MT dynamics and reorganization as done by MCAK, a MT-depolymerizing kinesin (Lee et al, 2008). Second, up-regulation at late G 2 through metaphase may be required in positioning of the spindle poles through interaction with astral MTs in early mitotic cells.…”

Shaping microtubules into diverse patterns: Molecular connections for setting up both ends

“…Another example is the direct association of EB1 family members with MCAK, a potent microtubule depolymerase [Lee et al, 2008]. In an in vitro reconstitution system, EB3, which facilitates tubulin assembly, targets MCAK to the growing microtubule ends and enhances the capacity of MCAK to induce catastrophes, resulting in increase of overall microtubule dynamicity in the system [Montenegro Gouveia et al, 2010].…”

The microtubule-associated protein MAPRE2 is involved in perineural invasion of pancreatic cancer cells

“…Human MAPRE1 (EB1), MAPRE2 (EB2/RP1), and MAPRE3 (EB3/EBF3) have been shown to associate with microtubules both in vivo and in vitro (17)(18)(19). These microtubule associated proteins display specific localization to growing plus ends of the microtubules, thereby regulating their dynamics (19).…”