# The Role of Retroelements in Centromere Function

> **NIH NIH R01** · UNIVERSITY OF CONNECTICUT STORRS · 2022 · $439,100

## Abstract

The essential function of centromeres in chromosome segregation during cell division requires a 
complex cascade of epigenetic events involving changes to chromatin character and kinetochore 
assembly. Kinetochore formation during mitosis is the culmination of a cycle defined by the “loading”, 
or deposition, of newly synthesized CENP-A, a variant histone, into centromeric chromatin. CENP-Atis 
faithful assembly during late telophase/early G1 of the cell cycle is facilitated by its histone 
chaperone, HJURP. This assembly cascade is sensitive to perturbation by genetic, epigenetic and 
environmental insults, with catastrophic consequences for genome/cell stability, but the genomic 
elements that guide accurate CENP-A nucleosome assembly are not well understood. A central 
conundrum in understanding the genomic features that aQract CENP-A nucleosome assembly is the 
observation that established centromeres are replete with satellite DNA while de novo centromeres 
(e.g. neocentromeres) lack satellites, yet are defined by retroelements, such as LINE-1s. While it 
appears CENP-A nucleosome occupancy may not require specific DNA sequences, mounting evidence 
demonstrates that RNA is a critical component of the epigenetic cascade leading to faithful CENP-A 
nucleosome assembly. However, the sequence specificity, spatiotemporal requirements for and 
transcriptional regulation of these centromeric RNAs are currently unknown. In Preliminary Data, we 
show that centromeric retroelements (cenTEs) are sites of engaged RNA polymerase and are involved 
in the CENP-A assembly cascade at human centromeres, linking a common transcribed genomic feature 
to CENP-A assembly at both native and de novo centromeres in humans for the first time. Leveraging our 
expertise in centromere assembly, noncoding RNAs, chromosome engineering, and genomics, we have 
formulated three aims, each with an innovative approach that will allow us to provide an unbiased 
assessment of where within centromeres transcription initiates, when during the cell cycle transcript 
initiation and elongation occur, and how these transcripts mediate centromere nucleosome assembly. We 
will use chromosome engineering to directly test whether cenTEs and their transcriptional activity 
are sufficient to facilitate de novo centromere assembly on chromosomes. These engineered chromosomes 
provide a new model to study the processes guiding cenTE-mediated centromere assembly and 
stabilization, and to examine misregulated incorporation of centromeric histones. The outcomes of 
this study will fill a large gap in our current understanding of centromere assembly and maintenance 
in normal cells, and provide valuable insight into events underlying chromosome aberration presenting 
in human diseases, infertility, and cancers of high metastatic potential.

## Key facts

- **NIH application ID:** 10468779
- **Project number:** 5R01GM123312-04
- **Recipient organization:** UNIVERSITY OF CONNECTICUT STORRS
- **Principal Investigator:** Rachel O'Neill
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $439,100
- **Award type:** 5
- **Project period:** 2019-09-19 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10468779

## Citation

> US National Institutes of Health, RePORTER application 10468779, The Role of Retroelements in Centromere Function (5R01GM123312-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10468779. Licensed CC0.

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