Navigation Links
DNA replication protein also has a role in mitosis, cancer
Date:5/13/2012

CHAPEL HILL, N.C. The foundation of biological inheritance is DNA replication a tightly coordinated process in which DNA is simultaneously copied at hundreds of thousands of different sites across the genome. If that copying mechanism doesn't work as it should, the result could be cells with missing or extra genetic material, a hallmark of the genomic instability seen in most birth defects and cancers.

University of North Carolina School of Medicine scientists have discovered that a protein known as Cdt1, which is required for DNA replication, also plays an important role in a later step of the cell cycle, mitosis. The finding presents a possible explanation for why so many cancers possess not just genomic instability, but also more or less than the usual 46 DNA-containing chromosomes.

The new research, which was published online ahead of print by the journal Nature Cell Biology, is the first to definitively show such a dual role for a DNA replication protein.

"It was such a surprise, because we thought we knew what this protein's job was to load proteins onto the DNA in preparation for replication," said Jean Cook, PhD, associate professor of biochemistry and biophysics and pharmacology at the UNC School of Medicine and senior study author. "We had no idea it also had a night job, in a completely separate part of the cell cycle."

The cell cycle is the series of events that take place in a cell leading to its growth, replication and division into two daughter cells. It consists of four distinct phases: G1 (Gap 1), S (DNA synthesis), M (mitosis) and G2 (Gap 2). Cook's research focuses on G1, when Cdt1 places proteins onto the genetic material to get it ready to be copied.

In this study, Cook ran a molecular screen to identify other proteins that Cdt1 might be interacting with inside the cell. She expected to just find more entities that controlled replication, and was surprised to discover one that was involved in mitosis. That protein, called Hec1 for "highly expressed in cancer," helps to ensure that the duplicated chromosomes are equally divided into daughter cells during mitosis, or cell division. Cook hypothesized that either Hec1 had a job in DNA replication that nobody knew about, or that Cdt1 was the one with the side business.

Cook partnered with Hec1 expert Edward (Ted) D. Salmon, PhD, professor of biology and co-senior author in this study, to explore these two possibilities. After letting Cdt1 do its replication job, the researchers interfered with the protein's function to see if it adversely affected mitosis. Using a high-powered microscope that records images of live cells, they showed that cells where Cdt1 function had been blocked did not undergo mitosis properly.

Once the researchers knew that Cdt1 was involved in mitosis, they wanted to pinpoint its role in that critical process. They further combined their genetic, microscopy and computational methods to demonstrate that without Cdt1, Hec1 fails to adopt the conformation inside the cells necessary to connect the chromosomes with the structure that pulls them apart into their separate daughter cells.

Cook says cells that make aberrant amounts of Cdt1, like that seen in cancer, can therefore experience problems in both replication and mitosis. One current clinical trial is actually trying to ramp up the amount of Cdt1 in cancer cells, in the hopes of pushing them from an already precarious position into a fatal one.


'/>"/>

Contact: Les Lang
llang@med.unc.edu
919-966-9366
University of North Carolina School of Medicine
Source:Eurekalert  

Related biology news :

1. JDRF-funded researchers discover proteins regulating human beta cell replication
2. Visualizing virus replication in three dimensions
3. New strategy for inhibiting virus replication
4. CSHL scientists uncover role of protein critical for activating DNA replication
5. Retrovirus replication process different than thought
6. Chimerix Antiviral CMX001 Inhibits JC Virus Replication in Preclinical Study; Late-Breaker Presented at Antiviral Congress 2010
7. Collisions of protein machines cause DNA replication derailment
8. Research into chromosome replication reveals details of heredity dynamics
9. In vitro infection and replication of hepatitis E virus in human hepatocytes
10. UBC megapixel DNA replication technology promises faster, more precise diagnostics
11. Study reveals new role for RNA interference during chromosomal replication
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
DNA replication protein also has a role in mitosis, cancer
(Date:6/14/2017)... IBM ) is introducing several innovative partner startups at VivaTech ... startups and global businesses, taking place in Paris ... will showcase the solutions they have built with IBM Watson ... France is one of the most dynamic ... in the number of startups created between 2012 and 2015*, ...
(Date:5/16/2017)... , May 16, 2017  Veratad Technologies, LLC ( ... online age and identity verification solutions, announced today they ... Conference 2017, May 15 thru May 17, 2017, in ... and International Trade Center. Identity impacts ... and in today,s quickly evolving digital world, defining identity ...
(Date:5/6/2017)... SINGAPORE , May 5, 2017 ... has just announced a new breakthrough in biometric ... that exploits quantum mechanical properties to perform ... new smart semiconductor material created by Ram Group ... across finance, entertainment, transportation, supply chains and security. ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... Singh Biotechnology today announced ... to SBT-100, its novel anti-STAT3 (Signal Transducer and Activator of Transcription 3) B ... to cross the cell membrane and bind intracellular STAT3 and inhibit its function. ...
(Date:10/10/2017)... ... 2017 , ... For the second time in three years, ... Award. Representatives of the FirstHand program travelled to Washington, D.C. Tuesday, October 10th, ... mission is to change the trajectory of STEM education in America by dramatically ...
(Date:10/10/2017)... , Oct. 10, 2017 SomaGenics announced the ... NIH to develop RealSeq®-SC (Single Cell), expected to be ... small RNAs (including microRNAs) from single cells using NGS ... the need to accelerate development of approaches to analyze ... "New techniques for measuring levels of mRNAs ...
(Date:10/9/2017)... Oct. 9, 2017  BioTech Holdings announced today ... which its ProCell stem cell therapy prevents limb ... The Company, demonstrated that treatment with ProCell resulted ... saved as compared to standard bone marrow stem ... resulted in reduction of therapeutic effect.  ...
Breaking Biology Technology: