In today’s more health conscious world, we’ve seen a surge in organic-everything. Enriching anything with sugar is a definite no-no. Good thing researchers play by their own rules. A University of Chicago research team led by Chuan He recently enriched the latest entrant to DNA methylation marks, 5-hmC, by enriching with glucose in a really tasty approach.
We recently highlighted an innovative 5-hmC detection method, which adds a glucose molecule to 5-hmC, protecting it from cleavage by certain restriction enzymes.
Using a similar approach, He’s team treated genomic DNA with a viral enzyme (ß-glucosyltransferase) that transfers a glucose moiety to the hydroxyl group of 5-hmC. But this new method goes one step further by using glucose that’s chemically modified with an azide group. Once the modified sugar gets added to 5-hmC, a biotin group can be tacked on by click chemistry. From there, affinity purification of DNA fragments containing the biotin-labeled 5-hmC enabled 5-hmC quantitation and deep sequencing.
The researchers made some interesting discoveries with their sensitive new method:
- The modification is present in more cell lines than previously recognized
- 5-hmC distribution differed from that of 5-mC, being enriched specifically in gene bodies and gene-proximal regions
- 5-hmC was enriched in highly expressed genes
- genes linked to hypoxia and angiogenesis showed increased levels of 5-hmC
- in older mice, 5-hmC was associated with genes implicated in neurodegenerative disorders
Enrich your 5’hmC knowledge at Nature Biotechnology, December 2010.