# The Mechanism of Spindle Assembly and Chromosome Alignment

> **NIH NIH R01** · CARNEGIE INSTITUTION OF WASHINGTON, D.C. · 2021 · $355,366

## Abstract

ABSTRACT
Through analyzing the spindle matrix proteome, which we defined in our previous funding periods, we have
made a number of exciting observations. Most importantly we have demonstrated that the spindle matrix
protein, BuGZ, undergoes oligomerization via phase transition or coacervation to form liquid droplets in vitro
mediated in part by the hydrophobic residues found in the intrinsically disorder region of BuGZ. The
coacervation activity of BuGZ is essential for assembly of the spindle and its matrix. BuGZ coacervation in vitro
as pure protein or in the spindle matrix concentrates tubulin and promotes MT assembly and bundling. Our
published and unpublished findings suggest that the interaction and/or coacervation of BuGZ and another
spindle assembly factor, TPX2, promotes spindle assembly. Here we propose to use biophysical, biochemical,
and cell biological approaches to dissect the molecular mechanism by which these spindle assembly factors
synergize to regulate Aurora A activation, microtubule assembly, and kinetochore-microtubule interactions in
mitosis.

## Key facts

- **NIH application ID:** 10246849
- **Project number:** 5R01GM130134-04
- **Recipient organization:** CARNEGIE INSTITUTION OF WASHINGTON, D.C.
- **Principal Investigator:** Yixian Zheng
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $355,366
- **Award type:** 5
- **Project period:** 2018-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10246849

## Citation

> US National Institutes of Health, RePORTER application 10246849, The Mechanism of Spindle Assembly and Chromosome Alignment (5R01GM130134-04). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10246849. Licensed CC0.

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