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Controlled phosphate intake prevents cellular toxicity

Phosphorus is one of the basic building blocks for all organisms. It helps form the basis of DNA, RNA and cell membranes. But when is too much of a good thing bad?

Penn State College of Medicine researchers have a better understanding of how cells control the intake and assimilation of phosphorous, a key element needed for biological processes. In a study published in the Proceedings of the National Academy of Sciences, they describe that bacteria limit uptake of inorganic orthophosphate (Pi) to avoid the disruption of magnesium-dependent processes.

Mauricio Pontes, assistant professor of pathology and laboratory medicine and of microbiology and immunology, and a team of researchers identified how physiological processes are disrupted by excessive amounts of Pi and demonstrated how bacteria regulate the uptake of phosphorous based on levels of magnesium available in their cytoplasm.

Adenosine triphosphate (ATP) is a source of energy for cells that requires magnesium ions to achieve a biologically functional form. Through experimentation, Pontes uncovered that when the bacterium Salmonella enterica serovar Typhimurium experiences a lack of magnesium ions, a protein inhibits the cell from taking in additional Pi needed to make ATP – which, if accumulated, can hinder bacterial growth and viability. Further studies also showed that even when magnesium ion levels in the cytoplasm are sufficient, too much intake of Pi can increase the production of ATP, which can deplete magnesium ions in the cytoplasm, then limiting protein synthesis and hindering growth.

Read more about Pontes’ findings in the Proceedings of the National Academy of Sciences

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