Work

Infrared Laser Heating Reveals a Reversible Phase Transition of Phosphofructokinase 1 in Mammalian Cells

Year: 2026

Type: article

Abstract: Metabolic enzymes can operate in concerted networks, so-called metabolons. The glucosome is a multi-enzyme complex that includes enzymes of glycolysis and gluconeogenesis and regulates glucose metabolism in mammalian cells. The mechanism of how glucosomes assemble remains largely unknown. Fluorescence recovery after photobleaching (FRAP) experiments suggest that glucosomes are liquid-like, but direct evidence of a phase transition mechanism is missing. Here, we developed a novel method to measure the phase transition of condensates in living cells by combining infrared laser heating with confocal microscopy of fluorescently labeled phosphofructokinase 1 liver-type (PFKL). We showed that glucosomes form and dissolve reversibly in HeLa cells upon temperature modulation, allowing us to determine the condensation temperature. We studied cells under osmotic stress to show that glucosomes retain their phase behavior despite a significant decrease in the mobility of PFKL. We propose that this method is a versatile tool to study the phase behavior of biomolecular condensates, yielding complementary information to well-established techniques such as FRAP.

Source: Chemistry - A European Journal

DOI: 10.1002/chem.71500

Authors: Morten Mosbach, Sneha Pavanan Kuruvanthara, Lukas Johannknecht, Simon Ebbinghaus

Institution: Ruhr University Bochum

Language: English

Topic: RNA Research and Splicing

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $4,640

Funder: Deutsche Forschungsgemeinschaft