# Mechano-molecular regulation of kinetochore function

> **NIH NIH R01** · UNIVERSITY OF MASSACHUSETTS AMHERST · 2022 · $313,116

## Abstract

PROJECT SUMMARY & ABSTRACT
Chromosome mis-segregation results in a pathological cellular condition called aneuploidy. Aneuploidy causes
a majority of miscarriages in the first trimester, birth defects, and has been linked to tumorigenesis and metas-
tasis. The accuracy of cell division depends on chromosomes becoming bioriented, a configuration where each
sister chromatid is attached to microtubules (MTs) from opposing spindle poles. Force and the tension that it
produces are integral to high fidelity transmission of the genome. Bioriented attachments become stabilized by
tension generated across the kinetochore (KT) – a large protein complex that fulfills two essential functions as
(1) the link between chromosomes and spindle MTs and (2) the regulatory hub for a spindle assembly check-
point (SAC) that delays anaphase onset until chromosomes are attached to spindle MTs and bioriented. Intrin-
sically disordered proteins (IDPs), which are proteins that do not have reproducible folds or tertiary structures,
are abundant at the KT and on the surface of chromosomes. In fact, ~50% of the molecular mass of the Dro-
sophila KT is predicted to be intrinsically disordered while an IDP enriched compartment called the perichro-
mosomal layer accounts for >30% of the mitotic chromosome mass. This proposal studies the function of “un-
structure” – specifically the role of intrinsically disordered proteins (IDPs) in cell division. The long-term goal is
to describe the fundamental molecular properties of cell division and, in doing so, to identify cellular processes
that can be targeted by therapies to control aneuploidy. The objective of this proposal is to combine in vitro bi-
ochemical and biophysical assays with live-cell experimentation in D. melanogaster and human tissue culture
cells to study conserved IDPs involved in cell division. The central hypothesis is that mechano-sensing and
force-transducing IDPs, which localize to KTs, centromeres and chromatin, harness force-generation by dy-
namic spindle MTs to regulate spindle assembly checkpoint (SAC) signaling and chromosome movement. The
rationale underpinning the research is based on the fact that the IDPs of interest are uniquely positioned to ex-
perience MT-dependent forces. The central hypothesis will be tested with three specific aims. Aim 1 will focus
on regulation of a checkpoint protein-KT interaction that we hypothesize is mechanical in nature. The goal of
aim 2 is to characterize a novel cup structure assembled around KTs that is coated with a SAC protein and that
we hypothesize is enriched for IDPs. Aim 3 will study the contribution of a very large protein, which is 97% dis-
ordered, called Ki-67 to cell division. Completion of these aims is expected to significantly impact basic
knowledge of force-transducing IDPs to the fidelity of cell division. The approach is innovative because it pairs
cell-based experiments including the use of live-cell force sensors with single molecule biophysical...

## Key facts

- **NIH application ID:** 10436323
- **Project number:** 5R01GM107026-09
- **Recipient organization:** UNIVERSITY OF MASSACHUSETTS AMHERST
- **Principal Investigator:** Thomas Joseph Maresca
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $313,116
- **Award type:** 5
- **Project period:** 2013-09-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10436323

## Citation

> US National Institutes of Health, RePORTER application 10436323, Mechano-molecular regulation of kinetochore function (5R01GM107026-09). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10436323. Licensed CC0.

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