Cell pH sensor mapped at atomic level for first time

GPR30 is a receptor on cell membranes that responds to bicarbonate, a molecule involved in regulating pH levels in and around cells. Until now, it was unclear exactly how that receptor works and what binds to it. The researchers mapped the structure of GPR30 using cryo-electron microscopy, a technique that can image molecules at near-atomic resolution. The study was published in the journal eLife and resolves the receptor at 3.15 ångströms.

The structure reveals precisely where bicarbonate binds to the receptor, and which regions of the receptor are essential for that interaction. Mutations introduced at those critical sites substantially reduced receptor activation in laboratory tests. That confirms the identified structure is functionally relevant, not merely a snapshot of an inactive molecule.

Why pH regulation connects to aging

Tissue acidity shifts with aging and with various diseases. Disrupted pH balance (acid-base homeostasis) is involved in kidney disease, certain heart conditions, and potentially in how cancer cells behave. GPR30 is one of the receptors that helps cells respond quickly to those changes. A clearer understanding of how it works could assist in developing drugs that steer how cells respond to pH fluctuations.

Until now, no pharmacologically recognized drug had been shown to act specifically on GPR30. The structural analysis gives researchers a blueprint for designing molecules that activate or inhibit the receptor. That is a standard first step in drug development.

Still early in development

The study provides a structural foundation, not a drug. Pharmacological development based on structural data typically takes years. GPR30 is also a relatively understudied receptor, meaning its broader biological role in living human tissue across different ages remains largely open. The findings are promising, but the distance to clinical application is still considerable.

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