Researchers Expand Role Of Mitochondria In Cell Division

A new study published in the open-access journal PLoS
Genetics reports that mitochondria in yeast cells
are very influential in the process of cell division.



Biochemist Heidi M. Blank and colleagues from Texas AgriLife Research
indicate that mitochondria are the fuel of the cell and act as a type
of "driver" in cell division. The authors maintain that this knowledge
of mitochondria's role may help find cures for several human diseases.
Not only do mitochondria generate about 90% of the cell's energy, but
they may also tell the cell how fast to divide, according to the
researchers.



"The finding changes the traditional view of the mitochondrion from an
'energy depot' at the service of its larger cellular host to a 'command
center' that directs cell division," said Michael Polymenis, co-author
of the study.



The biochemists used regular baker's years - the same type responsible
for breads, wines, and beers - because of its similarity to human cells
in terms of its processes. Co-author Mary Bryk notes that, "From
unicellular yeast to complex mammals, the process is the same. The job
of a cell is to divide and grow. Metabolism takes in 'food' and turns
it into fuel and building blocks for DNA replication and gene
expression."



Diseases are potential results if these cellular processes fail.
Typical cancer cells tend to have too much cell division too rapidly.
On the other hand, mitochondrial deficiencies that result in poor
metabolism can encourage damage to the brain, heart, skeletal muscles,
and liver.



Polymenis indicated that, "All of the body processes that require a lot
of energy are impacted by this. In fact, at least 1 in every 4,000
people worldwide suffer from mitochondrial deficiencies that result in
problems with normal development, motor control, vision, hearing, or
liver and kidney function." However, quick cell division may be
advantageous if trying to accelerate a healing wound or in some
agricultural applications.



"If we can understand the basic pathway that regulates cell division,
we can think of ways to tweak the different steps in that path with
therapeutics to help people who have problems with these high-energy
organs," said Bryk. This current research demonstrated that the yeast
cell's mitochondria decided to give the signal, the message was
received by the cell's nucleus, and cell division began.



"So now we need to connect that link," concluded Polymenis. "We need to
understand how and when the mitochondria send the message. If we know
how the message is sent, we might be able to control it."



An Increase in Mitochondrial DNA Promotes Nuclear DNA
Replication in Yeast

Blank HM, Li C, Mueller JE, Bogomolnaya LM, Bryk M, et al.

PLoS Genetics (2008). 4(4):e1000047.

doi:10.1371/journal.pgen.1000047

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Here to View Article



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Written by: Peter M Crosta