Nav: Home

Cell biology: Positioning the cleavage furrow

January 11, 2018

Researchers from Ludwig-Maximilians-Universitaet (LMU) in Munich have identified a signaling pathway that restricts cleavage furrow formation to the mid-plane of the cell.

Cell division is a fundamental biological process which ensures that, following the replication of the mother cell's genome, the two sets of chromosomes are equally distributed between two daughter cells. Chromosomes are segregated by the spindle apparatus, which is made up of fibrous protein structures called microtubules. The spindle apparatus is anchored to the opposite poles of the cell and determines the position of the future cleavage site in the middle of the cell, where a contractile protein ring is assembled. LMU researchers led by cell biologist Dr. Esther Zanin, who heads an Emmy Noether Research Group at the LMU Biocenter, have identified a molecular signaling pathway that restricts formation of the contractile ring to the mid-plane of the mother cell. Their findings appear in the Journal of Cell Biology.

Correct segregation of the chromosomes requires precise positioning of the cleavage furrow to the mid-plane of the cell. To achieve this, the spindle apparatus sends out two signals. One of these actively stimulates formation of the contractile ring at the mid-plane of the cell while a second signal inhibits its assembly at the cell poles. The inhibitory signal is known to originate from the so-called astral microtubules, which project to the cell poles from the spindle apparatus. "However, the molecular constituents of this signal have remained unknown until now," says Zanin. "With the help of a newly developed and highly sensitive method, we have now shown in the nematode Caenorhabditis elegans - a popular model organism in cell biology - that the enzyme Aurora A is a central component of the inhibitory signal."

Aurora A, which is also present in human cells, is known to play a crucial role in the control of spindle assembly, and is activated on the astral microtubules. "We think that the active enzyme then diffuses from the astral microtubules to the cell membrane at the cell poles, where it suppresses formation of a contractile ring." Zanin explains. In multicellular organisms, the precise control of cell division is not only essential during embryonic development, but also in the adult organism. Defects in cell division can causes numerous diseases including cancers." A detailed understanding of this fundamental process is therefore a prerequisite for the development of more effective ways to treat and prevent such disorders," says Zanin.
-end-


Ludwig-Maximilians-Universität München

Related Chromosomes Articles:

Andalusian experts indicate new elements responsible for instability in chromosomes
The researchers state that RNA joins with DNA by chance or because of a disease, the structure of the chromatin, the protein envelope of the chromosomes is altered, causing breaks in the DNA.
Reconstruction of ancient chromosomes offers insight into mammalian evolution
Researchers have gone back in time, at least virtually, computationally recreating the chromosomes of the first eutherian mammal, the long-extinct, shrewlike ancestor of all placental mammals.
Newly discovered DNA sequences can protect chromosomes in rotifers
Rotifers are tough, microscopic organisms highly resistant to radiation and repeated cycles of dehydration and rehydration.
For keeping X chromosomes active, chromosome 19 marks the spot
After nearly 40 years of searching, Johns Hopkins researchers report they have identified a part of the human genome that appears to block an RNA responsible for keeping only a single X chromosome active when new female embryos are formed, effectively allowing for the generally lethal activation of more than one X chromosome during development.
Researchers assemble five new synthetic chromosomes
A global research team has built five new synthetic yeast chromosomes, meaning that 30 percent of a key organism's genetic material has now been swapped out for engineered replacements.
More Chromosomes News and Chromosomes Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...