Here is a missing link story that won't make evolutionary biologists crazy. Epigenetics is the most recent craze in science media discussions of biology, it analyzes specific patterns of chemical tags that overlay the DNA structure, determining how tightly the DNA is packaged and how accessible certain genes are to be switched on or off. Epigenetics shows us that the genetic code held within DNA represents only part of the blueprint of life. Because it is not understood, we even get speculation that voting preferences can be framed in termed of epigenetics, like in the brain. Yes, some argue that you can literally claim your political opposition is brain damaged because they don't agree with you about banning GMOs or gay marriage.
More seriously, as researchers have uncovered more and more epigenetic tags, they have begun to wonder how they are all connected. Research from the University of North Carolina School of Medicine has established the first link between the two most fundamental epigenetic tags, histone modification and DNA methylation, in humans. The study implicates the protein UHRF1 in the maintenance of these epigenetic tags. Because the protein has been found to be defective in cancer, the finding could help scientists understand not only how microscopic chemical changes can ultimately affect the epigenetic landscape but also give clues to the underlying causes of disease and cancer.
Mouse embryonic stem cells (blue, green) lose DNA methylation (red) in the absence of UHRF1.
Credit: Strahl Lab, UNC School of Medicine
"There's always been the suspicion that regions marked by DNA methylation might be connected to other epigenetic tags like histone modifications, and that has even been shown to be true in model organisms like fungus and plants," said senior study author Brian Strahl, PhD, associate professor of biochemistry and biophysics in the UNC School of Medicine and a member of UNC Lineberger Comprehensive Cancer Center. "But no one has been able to make that leap in human cells. It's been controversial in terms of whether or not there's really a connection. We have shown there is."
Strahl, along with his postdoctoral fellow Scott Rothbart, honed in on this discovery by using a highly sophisticated technique developed in his lab known as next generation peptide arrays. First the Strahl lab generated specific types of histone modifications and dotted them on tiny glass slides called "arrays." They then used these "arrays" to see how histone modifications affected the docking of different proteins. One protein – UHRF1 – stood out because it bound a specific histone modification (lysine 9 methylation on histone H3) in cases where others could not.
Strahl and his colleagues focused the rest of their experiments on understanding the role of UHRF1 binding to this histone modification. They found that while other proteins that dock on this epigenetic tag are ejected during a specific phase of the cell cycle, mitosis, UHRF1 sticks around. Importantly, the protein's association with histones throughout the cell cycle appears to be critical to maintaining another epigenetic tag called DNA methylation. The result was surprising because researchers had previously believed that the maintenance of DNA methylation occurred exclusively during a single step of the cell cycle called DNA replication.
"This role of UHRF1 outside of DNA replication is certainly unexpected, but I think it is just another way of making sure we don't lose information about our epigenetic landscape," said Strahl.
Published in Nature Structural&Molecular Biology
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Debunking: A President Of The US Could Order A Nuclear Attack At A Moments Notice On A Whim
- Who Is Trying To Destroy The Internet?
- A Dimuon Particle At 30 GeV In ALEPH ??
- Moon Science Surprises - More Interesting For Human Exploration Than A Boulder Plucked From An Asteroid?
- DDoS War: How Zombie Fridges Bit The Internet In The a$$ Today.
- President Obama, Why Humans On Mars Right Now Are Bad For Science
- Hearing Voices Again? It's More Common Than You Think
- "Yes, exactly. I go into it some more here:..."
- "Ok looks as if I need to do a teaser trailer so you know what is in the link, if you had clicked..."
- "Ffs of course its bloody real i dont get why people put things like well if it was real we would..."
- "Because your hundreds of thousands who read these things are scientifically illiterate and buy..."
- "Hi, thank you for an interesting read, Sorry for the (surely) naive question. You have remarked..."
- To Avoid Adult Dysfunction Start 'IN UTERO'
- ACSH Medical Director Named One Of America's Top Pediatricians, We're In The Economist, And More
- The Math of Hunting and Fishing: When to Work Together
- Placebo: Bubbles Of Nothing Are Still Not Something
- People Who Take Drugs May Be Likelier to Commit Suicide
- Improved 'Screen Time' Guidelines Could Make Parents & Kids Happier