Navigation Links
Researchers gain new insight on wonder of cell division
Date:12/4/2008

Biologists have discovered a mechanism that is critical to cytokinesis -- nature's completion of mitosis, where a cell divides into two identical daughter cells.

The researchers have opened a new window on the assembly and activity of a ring of actin and myosin filaments that contract to pinch a cell at just the right time. They focused on key proteins whose roles drive signaling mechanisms that promote the production of both linear and branching microfilaments along the inside surface membrane of a dividing cell. By down-regulating the production of branched microfilaments at the right time, the membrane may be more malleable and better able to pinch inward and complete cytokinesis.

The findings-- detailed in the Dec. 5 issue of the journal Science -- come from basic research using Caenorhabditis elegans (roundworm) embryos. The discovery provides more basic insight than immediate biomedical application, but the implications could lead to a fine-tuning of anti-cancer drug therapies or to isolating new targets for drugs to stop cancerous cell division, said Bruce Bowerman, professor of biology in the University of Oregon's Institute for Molecular Biology.

Bowerman and Karen Oegema of the Ludwig Institute for Cancer Research at the University of California, San Diego, were principal investigators of a seven-member team funded by the National Institutes of Health.

Scientists have theorized that the modulation of microfilament structure plays a role in healthy cell division. However, finding that such shape-shifting down-regulation specifically targets branched microfilaments assembly came as a surprise, Bowerman said.

C. elegans is used in many genetics research laboratories to discover basic requirements for the 20,000 genes that compose its genome; most of the genes are conserved in humans and carry out similar processes. Using these nematodes, Bowerman said, is allowing researchers to "find players inside that previously weren't known to be involved in cytokinesis."

The new research focused on enzymes targeted by the GAP domain of the protein CYK-4 that is part of a multi-protein complex called centralspindlin. This GAP domain functions as a GTPase activator, targeting protein switches called GTPases, which bind and hydrolyze guanosine triphosphate (GTP) to guanosine diphosphate (GDP). When GTPase is bound to GTP it acts as an on switch; when GTP is hydrolyzed to GDP, the switch is turned off.

The researchers found that deleting a GTPase called Rac could bypass the requirement for the GAP domain in CYK-4, Bowerman said. Because Rac GTPases promote branched microfilament assembly, this suggests that normally the CYK-4 GAP acts to down-regulate the production of branched microfilaments.

Previously CYK-4 had been thought to only down-regulate a different GTPase called RhoA, which promotes linear microfilament assembly. Thus these new results implicate the down-regulation of branched microfilaments at the cell cortex as a critical step in cell division.

"We have found a completely new way of thinking about how cells remodel their internal skeletons such that they undergo the shape changes needed to divide and produce daughter cells," Bowerman said. "Some of these proteins already are targets of some cancer drugs. Now we have the opportunity to study and understand how certain proteins stabilize microfilaments within cells and inhibit cell division, and how other proteins act to modulate the stiffness of a cell's membrane to allow them to undergo shape changes needed for cell division and proliferation."


'/>"/>

Contact: Jim Barlow
jebarlow@uoregon.edu
541-346-3481
University of Oregon
Source:Eurekalert  

Related medicine news :

1. HALT-C researchers: Interferon as long-term treatment for hepatitis C not effective
2. LA BioMed researchers among Southern California Super Doctors
3. Researchers discover new enzyme in cancer growth
4. Researchers identify cell group key to Lyme disease arthritis
5. Interferon needed for cells to remember how to defeat a virus, UT Southwestern researchers report
6. Children Tell Researchers: Well Get Fit if Its Fun
7. Researchers identify how binge drinking may drive heart disease
8. UCSD researchers identify potential new drug target for chronic leukemia
9. USC researchers identify novel approach for suppressing prostate cancer development
10. Researchers identify new leprosy bacterium
11. UT Southwestern researchers develop new strategy for broad spectrum anti-viral drugs
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Researchers gain new insight on wonder of cell division
(Date:6/23/2017)... (PRWEB) , ... June 23, 2017 , ... Goodcents Deli ... , The restaurant is located at 4210 SW 21st St. Topeka, Kan. 66604 (near ... owner of Graham Restaurant Group who owns three other locations in the Topeka and ...
(Date:6/23/2017)... (PRWEB) , ... June 23, 2017 , ... MD ... Florida. This is MD Now’s 28th facility overall and marks the urgent care center's ... located one mile North of The Falls shopping mall. The new clinic offers a ...
(Date:6/23/2017)... ... June 23, 2017 , ... ... planning, and related services to families and business owners in and around Lackawanna ... to benefit senior citizens in the area. , Meals on Wheels of NEPA ...
(Date:6/22/2017)... ... ... Branches, Inc. has been partnering with The Miami Foundation for over 9 years, ... on providing opportunity to low-income families and breaking the cycle of generational poverty. , ... support its , Climb to College & Career initiative which focuses on postsecondary success. ...
(Date:6/22/2017)... ... June 23, 2017 , ... Despite its pervasiveness, many ... reviews available that integrate basic science with clinical practice. Now, however, a timely review ... providing clinicians with insight into the etiology of NeuP and educating preclinical scientists on ...
Breaking Medicine News(10 mins):
(Date:6/7/2017)... , June 7, 2017 Endo International plc ... 7, 2017, the Hon. Joseph R. Goodwin , ... West Virginia , entered a case ... Pelvic Repair System Products Liability Litigation (the "MDL") that ... cases to provide expert disclosures on specific causation within ...
(Date:6/5/2017)... Neb. , June 5, 2017 ... in the United States . ... helps a fallen person up to an almost-standing ... easily assembled and operated by one assistant and does ... It is simple enough that a child can operate ...
(Date:5/30/2017)... , May 30, 2017 DarioHealth Corp. (NASDAQ: DRIO), ... data solutions, today announced that it will be presenting at the ... 8:00 AM PT. Erez Raphael , CEO, of DarioHealth will ... conference will be held on June 6th & 7th, 2017 at ... in the small / micro-cap space. ...
Breaking Medicine Technology: