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bioRxiv · 10.1101/2023.11.06.565735

The modified RNA base acp3U is an attachment site for N-glycans in glycoRNA

Xie, Y.·Hemberger, H.·Till, N. A.·Chai, P.·Watkins, C.·Lebedenko, C. G.·Caldwell, R. M.·George, B.·Bertozzi, C. R.·Garcia, B. A.·Flynn, R. A.
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Abstract

We recently identified glycoRNA--a previously undescribed glycoconjugate--which consists of RNAs modified with secretory N-glycans and presented on the cell surface. While previous work supported a covalent linkage between RNA and glycans, the direct chemical nature of the RNA-glycan connection was not described. Here we develop a sensitive and scalable protocol to detect and characterize native glycoRNAs. Leveraging periodate oxidation and aldehyde ligation (rPAL) and Sequential Window Acquisition of all Theoretical Mass Spectra (SWATH-MS), we identified the modified RNA base 3-(3-amino-3-carboxypropyl)uridine (acp3U) as a site of attachment of N-glycans in glycoRNA. The sensitivity and robustness of rPAL provided the first evidence of a direct glycan-RNA linkage, and its flexibility will enable further characterization of glycoRNA biology.

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Xie, Y., Hemberger, H., Till, N. A., Chai, P., Watkins, C., Lebedenko, C. G., Caldwell, R. M., George, B., Bertozzi, C. R., Garcia, B. A., Flynn, R. A.. 2023-11-06. The modified RNA base acp3U is an attachment site for N-glycans in glycoRNA. https://doi.org/10.1101/2023.11.06.565735

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