Phosphate polymer forms a cornerstone of metabolic control

Date:
October 15, 2020
Source:
Carnegie Institution for Science
Summary:
In a changing climate, understanding how organisms respond to
stress conditions is increasingly important. New work could
enable scientists to engineer the metabolism of organisms to be
more resilient and productive in a range of environments. Their
research focuses on polyphosphate, an energy-rich polymer of tens
to hundreds phosphate groups which is conserved in all kingdoms
of life and is integral to many cellular activities, including an
organism's ability to respond to changing environmental conditions.



FULL STORY ==========================================================================
In a changing climate, understanding how organisms respond to stress
conditions is increasingly important. New work led by Carnegie's Arthur Grossman and Emanuel Sanz-Luque could enable scientists to engineer the metabolism of organisms to be more resilient and productive in a range
of environments.


========================================================================== Their research focuses on polyphosphate, an energy-rich polymer of tens
to hundreds phosphate groups which is conserved in all kingdoms of life
and is integral to many cellular activities, including an organism's
ability to respond to changing environmental conditions.

"The ways in which polyphosphate synthesis and mobilization can
be integrated into a myriad of biological processes in a range of photosynthetic and non- photosynthetic organisms and various cell types
has been difficult to unravel," Grossman said. "Polyphosphate plays a
critical role in responding to environmental stresses, including high temperatures, exposure to toxic metals and, of particular interest to
us, nutrient deprivation." The research team -- which also included
Carnegie's Shai Saroussi, Weichao Huang, and Nicholas Akkawi --
investigated how the photosynthetic alga Chlamydomonas reinhardtii copes
with a sparsity of nutrients. Their findings were recently published in
Science Advances.

The team revealed that polyphosphate synthesis is deeply integrated with cellular metabolism, leveraging this relationship to shape the alga's
ability to adapt to challenges in its surroundings.

Using advanced techniques, the researchers showed that the synthesis of polyphosphate is crucial for maintaining the optimal energy balance,
enabling cellular physiological processes. When nutrient availability
is low, polyphosphate synthesis is necessary for the alga to adjust its cellular metabolism and survive the adverse conditions. It does this
by impacting the biochemical processes occurring in the cell's power
centers -- mitochondria which perform respiration and chloroplasts which perform photosynthesis.

If a cell's ability to synthesize polyphosphate is impaired, it is
unable to accomplish normal electron transport in the mitochondria and chloroplasts - - central to the functions of these key organelles -- compromising cellular regulation, fitness, and survival.

"It is possible that the role of polyphosphate synthesis and mobilization
in regulating the energetic functions of the cell under nutrient-limited conditions results in the creation of 'checkpoint' molecules within
chloroplast and mitochondria that guide changes in the genes expressed
in response to the environmental conditions," said lead author Sanz-Luque.

This knowledge could potentially be harnessed to improve the resilience
of other photosynthetic organisms and make them better able to survive
the stress of a changing climate.

Together Carnegie's Emanuel Sanz-Luque, Devaki Bhaya, and Arthur
Grossman also published a comprehensive review in Frontiers in Plant
Science detailing the ways in which polyphosphate integrate into the
metabolic networks and regulatory processes in a variety of photosynthetic organisms.


========================================================================== Story Source: Materials provided by
Carnegie_Institution_for_Science. Note: Content may be edited for style
and length.


========================================================================== Journal Reference:
1. E. Sanz-Luque, S. Saroussi, W. Huang, N. Akkawi, A. R. Grossman.

Metabolic control of acclimation to nutrient deprivation dependent
on polyphosphate synthesis. Science Advances, 2020; 6 (40):
eabb5351 DOI: 10.1126/sciadv.abb5351 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201015134210.htm

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