The ends of growing microtubules (MTs) accumulate a set of diverse factors known as MT plus end-tracking proteins (+TIPs), which control microtubule dynamics and organization. In this paper, we identify SLAIN2 as a key component of +TIP interaction networks. We showed that the C-terminal part of SLAIN2 bound to end-binding proteins (EBs), cytoplasmic linker proteins (CLIPs), and CLIP-associated proteins and characterized in detail the interaction of SLAIN2 with EB1 and CLIP-170. Furthermore, we found that the N-terminal part of SLAIN2 interacted with ch-TOG, the mammalian homologue of the MT polymerase XMAP215. Through its multiple interactions, SLAIN2 enhanced ch-TOG accumulation at MT plus ends and, as a consequence, strongly stimulated processive MT polymerization in interphase cells. Depletion or disruption of the SLAIN2-ch-TOG complex led to disorganization of the radial MT array. During mitosis, SLAIN2 became highly phosphorylated, and its interaction with EBs and ch-TOG was inhibited. Our study provides new insights into the molecular mechanisms underlying cell cycle-specific regulation of MT polymerization and the organization of the MT network.

dx.doi.org/10.1083/jcb.201012179, hdl.handle.net/1765/33404
The Journal of Cell Biology
Erasmus MC: University Medical Center Rotterdam

van der Vaart, B, Manatschal, C, Grigoriev, I, Olieric, V, Gouveia, S.M, Bjelić, S, … Akhmanova, A.S. (2011). SLAIN2 links microtubule plus end-tracking proteins and controls microtubule growth in interphase. The Journal of Cell Biology, 193(6), 1083–1099. doi:10.1083/jcb.201012179