PRL-1/2 phosphatases control TRPM7 magnesium-dependent function to regulate cellular bioenergetics

Area of Science:

• Cellular Biology
• Molecular Mechanisms of Ion Transport
• Biochemistry

Background:

• Phosphatases of regenerating liver (PRL-1, PRL-2, PRL-3) are implicated in regulating intracellular magnesium levels.
• The interaction between PRLs and CNNM magnesium transport regulators is known, but the precise mechanism of magnesium transport remains unclear.

Purpose of the Study:

• To elucidate the mechanism of magnesium transport regulated by the PRL-CNNM complex.
• To investigate the role of ARL15 and PRL-2 in modulating CNNM3 and TRPM7 interactions.
• To understand how PRLs and CNNM3 influence TRPM7 channel activity and cellular metabolism.

Main Methods:

• Development of a genetically encoded intracellular magnesium-specific reporter.
• Analysis of protein-protein interactions using co-immunoprecipitation and other biochemical assays.
• Overexpression and knockdown studies of PRLs, CNNM3, and ARL15 to assess TRPM7 channel function.

Main Results:

• CNNM family proteins inhibit the TRPM7 magnesium channel.
• ARL15 promotes CNNM3/TRPM7 complex formation, reducing TRPM7 activity.
• PRL-2 overexpression disrupts the CNNM3-TRPM7 interaction, enhancing TRPM7 function.
• PRL-1/2 promote TRPM7-induced signaling, while CNNM3 overexpression inhibits it.
• Cellular magnesium levels and PRL activity dynamically regulate CNNM3-TRPM7 interaction.
• Co-targeting TRPM7 and PRL-1/2 affects mitochondrial function and metabolic stress response.

Conclusions:

• PRL-1/2 dynamically regulate TRPM7 channel activity through interactions with CNNM3.
• This regulation coordinates magnesium transport and reprograms cellular metabolism, particularly under metabolic stress.
• Findings provide insights into the molecular mechanisms controlling intracellular magnesium homeostasis.