Jinan, May 31 (Xinhua) -- Human cells are like a sophisticated communication city, with a large number of "instructions" being transmitted every day, regulating life activities such as mood and metabolism. The "receivers" of these instructions are a class of proteins called G protein-coupled receptors (GPCRs), which act like "antennas" distributed on the cell surface, responsible for capturing external signals such as hormones and neurotransmitters.
There are more than 800 types of GPCRs in the human body, which transmit instructions downward through only 39 "signal relay officers" (16 Gα proteins, 5 Gβ proteins, 14 Gγ proteins, and 4 Arrestin proteins), yet they precisely regulate tens of thousands of different physiological and pathological functions. This phenomenon of "few relays, multiple tasks" indicates that there is an extremely exquisite "signal organization mechanism" within cells.
For a long time, scientists have focused their research on a key protein called β-arrestin, which is considered one of the core "shunters" of GPCR signal transduction. However, whether endogenous β-arrestin can spontaneously form condensates with specific functions, whether its "assembly" process is precisely regulated by different GPCRs, the molecular mechanism of condensation formation, and whether this condensate directly determines the physiological functions of GPCRs have always lacked clear answers.
Recently, the international academic journal Nature published online the research results of Professor Sun Jinpeng's team and Professor Xiao Peng's team from Shandong University, together with expert teams from Duke University in the United States. This study confirmed for the first time that the β-arrestin protein is not a static "scaffold" as traditionally thought, but can spontaneously form "dynamic condensates" with droplet characteristics, acting as a "signal assembly platform" within cells, achieving local enrichment and precise regulation of signals at the nanoscale.
"Different GPCR receptors can induce differentiated 'clustering modes,' which means different signal towers tell β-arrestin to build information stations in different ways, allowing various life signals to be accurately transmitted in independent intervals without interference," said Sun Jinpeng, corresponding author of the paper and dean of the Advanced Medical Research Institute of Shandong University.
This study directly links the "phase separation" mechanism to the regionalized signals of GPCRs for the first time, clarifying the core role of β-arrestin condensates as a "regionalized organization platform." This discovery provides a new theoretical framework for understanding the "regionalized transduction" of GPCR signals and offers a new perspective for deciphering the underlying logic of cell signal regulation.
At the same time, this discovery opens up a new direction and provides new targets for the development of targeted drugs for major diseases such as neurological diseases, tumors, and metabolic diseases. "The essence of many diseases is that cell signals are in disorder. If we can regulate the formation or dissociation of β-arrestin condensates, it is like adding an adjustable 'switch' to the signal system, achieving precise intervention of disease-related signaling pathways and promoting the development of precision medicine," Sun Jinpeng said.
