The Borealin dimerization domain interacts with Sgo1 to drive Aurora B-mediated spindle assembly.

The chromosomal passenger complex (CPC), which includes the kinase Aurora B, is a master regulator of meiotic and mitotic processes that ensure the equal segregation of chromosomes. Sgo1 is thought to play a major role in the recruitment of the CPC to chromosomes, but the molecular mechanism and contribution of Sgo1-dependent CPC recruitment is currently unclear. Using egg extracts and biochemical reconstitution, we found that Sgo1 interacts directly with the dimerization domain of the CPC subunit Borealin.

SAS-6 Association with γ-Tubulin Ring Complex Is Required for Centriole Duplication in Human Cells.

Centrioles are essential components of centrosome, the main microtubule-organizing center of animal cells required for robust spindle bipolarity [1, 2]. They are duplicated once during the cell cycle [3], and the duplication involves assembly of a cartwheel on the pre-existing centriole followed by assembly of triplet microtubules around the cartwheel [4, 5]. Although the molecular details of cartwheel formation are understood [6-13], the mechanisms initiating the formation of centriolar microtubules are not known.

EB1 regulates attachment of Ska1 with microtubules by forming extended structures on the microtubule lattice.

Kinetochore couples chromosome movement to dynamic microtubules, a process that is fundamental to mitosis in all eukaryotes but poorly understood. In vertebrates, spindle-kinetochore-associated (Ska1-3) protein complex plays an important role in this process. However, the proteins that stabilize Ska-mediated kinetochore-microtubule attachment remain unknown.

Human SAS-6 C-Terminus Nucleates and Promotes Microtubule Assembly in Vitro by Binding to Microtubules.

Centrioles are essential components of the animal centrosome and play crucial roles in the formation of cilia and flagella. They are cylindrical structures composed of nine triplet microtubules organized around a central cartwheel. Recent studies have identified spindle assembly abnormal protein SAS-6 as a critical component necessary for formation of the cartwheel.

+TIP EB1 downregulates paclitaxel‑induced proliferation inhibition and apoptosis in breast cancer cells through inhibition of paclitaxel binding on microtubules.

Microtubule plus‑end‑binding protein (+TIP) EB1 has been shown to be upregulated in breast cancer cells and promote breast tumor growth in vivo. However, its effect on the cellular actions of microtubule‑targeted drugs in breast cancer cells has remained poorly understood. By using cellular and biochemical assays, we demonstrate that EB1 plays a critical role in regulating the sensitivity of breast cancer cells to anti‑microtubule drug, paclitaxel (PTX).

Microtubule +TIP protein EB1 binds to GTP and undergoes dissociation from dimer to monomer on binding GTP.

The +TIP protein EB1 autonomously tracks the growing plus end of microtubules and regulates plus-end dynamics. Previous studies have indicated that EB1 can recognize GTP-bound tubulin structures at the plus end, and it localizes on the microtubule surface at a site close to the exchangeable GTP-binding site of tubulin. Although the GTP-dependent structural change in tubulin has been demonstrated to be a critical determinant for recognition of plus ends by EB1, the effect of GTP on the structure of EB1 has remained unclear.