Inner 'clockwork' sets the time for cell division in bacteria

February 10, 2020

Researchers at the Biozentrum of the University of Basel have discovered a "clockwork" mechanism that controls cell division in bacteria. In two publications, in "Nature Communications" und "PNAS", they report how a small signaling molecule starts the "clock", which informs the cell about the right time to reproduce.

The ability of pathogens to multiply in the host is crucial for the spread of infections. The speed of bacterial division greatly depends on the environmental conditions. Under unfavorable conditions, such as nutrient deficiency, bacteria tend to pause after division and reproduce more slowly. But how do bacteria know, when it is time to enter the next round of cell division?

A team at the Biozentrum of the University of Basel, led by Prof. Urs Jenal has now identified a central switch for reproduction in the model bacterium Caulobacter crescentus: the signaling molecule c-di-GMP. In their current study, published in the journal Nature Communications, they report that this molecule initiates a "clock-like" mechanism, which determines whether individual bacteria reproduce.

A signaling molecule regulates "clockwork" in bacteria

How long a cell pauses after division and how it then decides to engage in the next round of division is still poorly understood. The signaling molecule c-di-GMP plays a key role in this process. "The rise in the c-di-GMP level sets the individual cogwheels of the cell's clock into action, one after the other," explains Jenal. "These cogwheels are enzymes called kinases. They prepare the transition of the cell from the resting to the division phase."

Enzymes respond to c-di-GMP levels

Under favorable living conditions, newborn bacteria begin to produce the signaling molecule - this starts the clock ticking. The initially low c-di-GMP level activates a first kinase. This activates the expression of over 100 genes, which drive the cell towards division and boost the production of c-di-GMP.

The resulting peak levels of c-di-GMP finally stimulate the last wheel of the machinery, also a kinase. "With this step, the cell ultimately decides to replicate its DNA and to trigger cell division," explains Jenal. "Simultaneously the over 100 genes are switched off again, as these are only important for the transition phase but obstruct later stages of proliferation."

Insights into c-di-GMP mediated enzyme activation

In a parallel study, recently been published in PNAS, a team led by Prof. Tilman Schirmer, also at the Biozentrum of the University of Basel, describes how c-di-GMP activates the first cogwheel of the newly discovered clock at the atomic level.

The researchers have revealed that the mobile domains of the kinase are initially locked in a fixed position. The binding of c-di-GMP liberates the domains, thereby activating the kinase for gene expression. "In our study, we have discovered a new mode of c-di-GMP mediated activation," says Schirmer. "Once again, we are fascinated by the diverse ?strategies? of this small molecule to regulate biochemical processes."

Universal principle in bacterial reproduction

The c-di-GMP regulated timing of the bacterial cell cycle by this signaling molecule seems to be a universal mechanism. The researchers assume that this mechanism enables bacteria to precisely coordinate growth and development. The elucidation of this novel mechanism also contributes to a better understanding of the growth of bacterial pathogens.
-end-


University of Basel

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.