New DNA Found Hidden Inside Human Cells - Spokane, North Idaho News & Weather KHQ.com

New DNA Found Hidden Inside Human Cells

YAHOO.COM - Sixty years after scientists described the chemical code of life — an interweaving double helix called DNA — researchers have found four-stranded DNA is also lurking in human cells.

The odd structures are called G-quadruplexes because they form in regions of deoxyribonucleic acid (DNA) that are full of guanine, one of the DNA molecule's four building blocks, with the others being adenine, cytosine, thymine. The structure comprises four guanines held together by a type of hydrogen bonding to form a sort of squarelike shape. (The DNA molecule is itself a double strand held together by these building blocks and wrapped together like a helix.)

The new visualization of the G-quadruplex is detailed this week in the journal Nature Chemistry.

"I think this paper is important in showing directly the existence of this structure in vivo in the human genome, but it is not completely unexpected," said Hans-Joachim Lipps, of the University of Witten in Germany, who was not involved in the study. [See Images of the 4-Stranded DNA]

Scientists had shown in the past that such quadruplex DNA could form in test tubes and had even been found in the cells of ciliated protozoa, or single-celled organisms with hairlike appendages. Also there were hints of its existence in human cells, though no direct proof, Lipps said.

But scientists still didn't have concrete evidence for its existence in the human genome. In the new study, researchers, including chemist Shankar Balasubramanian, of the University of Cambridge and Cambridge Research Institute, crafted antibody proteins specifically for this type of DNA. The proteins were marked with a fluorescent chemical, so when they hooked up to areas in the human genome packed with G-quadruplexes, they lit up.

Next, they incubated the antibodies with human cells in the lab, finding these structures tended to occur in genes of cells that were rapidly dividing, a telltale feature of cancer cells. They also found a spike in quadruplexes during the s-phase of the cell cycle, or the phase when DNA replicates just before the cell divides.

As such, the researchers think the four-stranded DNA could be a target for personalized medicine in the future. If they could block these odd ducks perhaps they could stop the rapid cell division of cancer cells.

"We are seeing links between trapping the quadruplexes with molecules and the ability to stop cells dividing, which is hugely exciting," Balasubramanian said in a statement.

The finding "is certainly a technical (not scientific) breakthrough in designing antibodies sensitive enough to demonstrate this structure in vivo in the human genome," Lipps wrote.

Lipps and his colleagues had suggested previously these structures regulate basic biological mechanisms, such as the replication of DNA.

"What makes me personally very happy about this work is that it again demonstrates that mechanisms first described in ciliated protozoa hold also true for other organisms up to human, demonstrating the strength of this model organism," wrote Lipps wrote.

The team still has several questions about quadruplexes, such as how the structures operate. "One thought is that these quadruplex structures might be a bit of a nuisance during DNA replication — like knots or tangles that form," Balasubramanian said.

  • Most Popular StoriesMost Popular StoriesMore>>

  • Felon arrested after bragging to Moses Lake police on Facebook

    Felon arrested after bragging to Moses Lake police on Facebook

    Saturday, May 19 2018 5:19 PM EDT2018-05-19 21:19:17 GMT

    MOSES LAKE, Wash. - Here's a tip: If you're on the run from police, don't brag about getting away on their Facebook page. That's what 19-year-old Kayla Irizzary did before she was taken into custody early Saturday morning by Moses Lake Police. Officers say they first contacted the woman during a traffic stop last week. She was a passenger in the stopped car.

    >>

    MOSES LAKE, Wash. - Here's a tip: If you're on the run from police, don't brag about getting away on their Facebook page. That's what 19-year-old Kayla Irizzary did before she was taken into custody early Saturday morning by Moses Lake Police. Officers say they first contacted the woman during a traffic stop last week. She was a passenger in the stopped car.

    >>
  • 80th annual Spokane Lilac Festival Armed Forces Torchlight Parade draws crowd

    80th annual Spokane Lilac Festival Armed Forces Torchlight Parade draws crowd

    Sunday, May 20 2018 10:30 AM EDT2018-05-20 14:30:08 GMT

    SPOKANE, Wash. - For the 80th year, the Lilac Festival is hosting the largest Torchlight Military Parade in the nation. The streets of downtown Spokane will be filled with bands, floats military and equestrian groups, drill teams and dancers, cars and more.

    >>

    SPOKANE, Wash. - For the 80th year, the Lilac Festival is hosting the largest Torchlight Military Parade in the nation. The streets of downtown Spokane will be filled with bands, floats military and equestrian groups, drill teams and dancers, cars and more.

    >>
  • Deaf couple gets in fight with man who allegedly punched their service dog on plane

    Deaf couple gets in fight with man who allegedly punched their service dog on plane

    Monday, May 21 2018 6:35 PM EDT2018-05-21 22:35:34 GMT

    ORLANDO, Fla. - Federal authorities are investigating after police responded to a heated brawl in the middle of Orlando International Airport on Monday.  WOFL-TV reports Hazel Tamirez and her boyfriend Matt Silva are both hearing impaired. The couple was on a Frontier flight from Colorado Springs with their two kids and their Great Dane service dog. 

    >>

    ORLANDO, Fla. - Federal authorities are investigating after police responded to a heated brawl in the middle of Orlando International Airport on Monday.  WOFL-TV reports Hazel Tamirez and her boyfriend Matt Silva are both hearing impaired. The couple was on a Frontier flight from Colorado Springs with their two kids and their Great Dane service dog. 

    >>
HD DOPPLER 6i
/