Research Summary
The paper presents a characterization of processed and functionally
important lncRNAs deriving from human centromeres that bind the
centromeric histone variant CENP-A. A RIP-seq library targeting CENP-A
provided sequence reads that were used to construct 432 transcripts of
heterogeneous length (300-2500 bases). These transcripts mapped
confidently to almost every human chromosome, are enriched in
𝛼-satellite repeats, and are unique enough to permit separation into
four classes through two different clustering methods. Visualizing a
subset of these transcripts via RNA FISH in synchronized HeLa cells
revealed that multiple and unique 𝛼-satellite-containing RNAs are
present in the cell nucleus, and that individual cenRNAs (eg. cenRNA#4)
can be localized near one centromere via co-IF with centromere protein B
(CENP-B) in a fraction of cells. Both 𝛼-satellite-containing RNAs and
cenRNA#4 are likely polyadenylated as they can be amplified from cDNA
using poly-dT primers. Finally, siRNA-knockdown of 𝛼-satellite RNAs or
cenRNA#4 individually resulted in a higher rate of chromosomal
segregation defects compared to a scrambled siRNA target, lending
support to a functional role of these transcripts in maintaining
chromosome stability.