# Genomic Analysis of Centromere Assembly and Function

> **NIH NIH R01** · DUKE UNIVERSITY · 2020 · $333,784

## Abstract

Centromeres are essential to genome inheritance. Abnormal centromere function is associated with birth
defects, infertility, and cancer. Human centromeric (CEN) chromatin typically forms on alpha satellite DNA,
a 171bp monomeric sequence that is tandemly organized into large multi-megabase arrays. More than half of
endogenous human chromosomes have two distinct alpha satellite arrays, either of which can be the site of
centromere assembly. Using Homo sapiens chromosome 17 (HSA17) as a model, we demonstrated that in
most individuals, the centromere is formed at the primary alpha satellite array. Less frequently (30%), the
centromere assembles at the alternative array. We showed that centromere location is dictated by genomic
variation within the primary alpha satellite array. When the array contains extensive size and sequence
variation, the centromere is usually assembled at the alternative array nearby. However, if the centromere
forms at a variant array, the kinetochore is architecturally flawed, resulting in chromosome aneuploidy. The
molecular basis for how genomic variation affects centromere assembly and maintenance is not clear. Most
human chromosomes must choose between two (or more) locations at which to build a stable centromere, so
our work will address a fundamental gap in the knowledge of basic processes governing centromere choice
and chromosome stability. In this proposal, we will define molecular links between human centromere
assembly and genomic variation in alpha satellite DNA. The proposed work will test the hypothesis that alpha
satellite arrays containing variant higher order repeat (HORs) are sub-optimally organized for proper
kinetochore assembly. We also postulate that variant HORs produce unstable transcripts that cannot interact
appropriately with centromere proteins (CENPs). The experiments in this proposal will define the altered
molecular relationship of alpha satellite variation and centromere protein assembly by: 1) mapping alpha
satellite long-range organization of HORs and CENPs and characterizing RNA-CENP interactions at normal
and defective centromeres, 2) distinguishing if variant arrays are unable to recruit versus retain CENPs, 3)
using human artificial chromosome assembly assays to test the ability of variant arrays to assemble
centromeres de novo, and 4) repairing defective centromeres using CRISPR engineering. This proposal will
address mechanisms of centromere choice and assembly by focusing on the largely unexplored area of
genomic variation within highly repetitive DNA.

## Key facts

- **NIH application ID:** 9984479
- **Project number:** 5R01GM124041-04
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** BETH A SULLIVAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $333,784
- **Award type:** 5
- **Project period:** 2017-09-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9984479

## Citation

> US National Institutes of Health, RePORTER application 9984479, Genomic Analysis of Centromere Assembly and Function (5R01GM124041-04). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9984479. Licensed CC0.

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