bioRxiv Science⌕ Search

bioRxiv · 10.64898/2026.08.09.743761

GPR27 mediates L-lactate-induced Calcium and cAMP signalling in 3T3 cells

Abstract

GPR27/SREB1 is a highly conserved orphan class A G-protein coupled receptor implicated in insulin production, metabolic regulation, tumour biology, neurodegeneration and L-lactate homeostasis, but its immediate second-messenger signalling remains poorly defined. We used single-cell Forster resonance energy transfer nanosensors to monitor cytosolic Ca2+ and cAMP in wild-type 3T3 MEF cells, CRISPR-Cas9 GPR27-knockout cells (GPR27KO) and GPR27-knockout cells transiently re-expressing FLAG-tagged GPR27 (GPR27-rescued). The GPR27 surrogate agonist 8535n (1 {micro}M) increased intracellular Ca2+ in wild-type and rescued cells but not in GPR27-knockout cells and produced no significant cAMP response in wild-type cells. Basal Ca2+ and cAMP levels were unaffected by GPR27 deletion. Extracellular L-lactate (2 mM) induced a GPR27-dependent increase in Ca2+ and cAMP in wild-type and rescued cells, but not in knockout cells, raising the possibility that L-lactate acts as an endogenous ligand or modulator of GPR27. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/743761v1_ufig1.gif" ALT="Figure 1"> View larger version (10K): org.highwire.dtl.DTLVardef@15f6724org.highwire.dtl.DTLVardef@6ca9b6org.highwire.dtl.DTLVardef@1f9f841org.highwire.dtl.DTLVardef@197677_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIGPR27 surrogate agonist 8535n increases intracellular Ca2+ but not cAMP in 3T3 cells. C_LIO_LIExtracellular L-lactate induces GPR27-dependent intracellular Ca2+ and cAMP increases in 3T3 cells. C_LIO_LIThese findings identify GPR27 as a putative candidate lactate sensor. C_LI

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kuhanec, D., Sanjkovic, E., Zorec, T. M., Kreft, M., Chowdhury, H. H., Zorec, R.. 2026-08-11. GPR27 mediates L-lactate-induced Calcium and cAMP signalling in 3T3 cells. https://doi.org/10.64898/2026.08.09.743761

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

HUH-tag conjugation enables accessible, site-specific functionalization of DNA origami with signaling-competent proteins

DNA origami enables precise nanometer scale control over the number, spacing, and geometry of biomolecules, making it a powerful tool for dissecting spatially organized biological processes such as receptor signaling. However, functionalizing origami with proteins remains a bottleneck restricting the technology to specialized laboratories. Here we show that viral-derived HUH endonuclease tags, small (~10 kDa) domains that form a covalent phosphotyrosine bond with short unmodified ssDNA, provide a simple and cost-effective route to decorating DNA origami with functional proteins. Using interleukin-1{beta} (IL-1{beta}) as a model ligand, we generated recombinant IL-1{beta}-HUH, achieved efficient site-specific conjugation to unmodified ssDNA within minutes, and coupled the conjugates to a DNA origami pegboard with tunable stoichiometry. IL-1{beta}-functionalized origami triggered ligand-dependent signalling in living cells and allowed visualization of the recruitment of downstream signaling molecules, confirming that HUH-tag conjugation preserves functionality. Because this strategy requires only standard molecular biology equipment and unmodified DNA, it lowers a technical and financial barrier to DNA origami-based experimentation, opening the approach to a broader range of biological questions and laboratories outside the DNA nanotechnology field.

cell biology↗

Global mapping of VEGF-A driven changes in the RNA bound phospho-proteome reveals a molecular switch to coordinate angiogenesis in endothelial cells

RNA binding proteins (RBPs) serve as upstream master regulators of cellular fate transitions at the post-transcriptional level. RBP-RNA interactions are dynamically regulated by post-translational modifications to coordinate cellular responses. We hypothesised that changes in RBP phosphorylation will play a key role in coordinating angiogenesis, the formation of new blood vessels, in endothelial cells (ECs). Therefore, we used phospho-proteomic analysis of the mRNA bound proteome to identify global phosphorylation changes in mouse cardiac ECs during acute and prolonged VEGF-A stimulation. Of the differentially phosphorylated RBPs, we found that the phosphorylation of serine 199 within mRNA bound Phf6 (PHD finger protein 6) was consistently increased following VEGF-A stimulation. Phf6 phosphorylation at this specific site was sufficient and required to induce a pro-angiogenic phenotype, facilitating a change in Phf6 conformation promoting interaction with distinct RNAs. We show here that Phf6 phosphorylation at serine 199, downstream of VEGF-A, acts as a molecular switch to differentially coordinate a decrease of anti-angiogenic RNAs (i.e. extracellular matrix genes) and an increase in pro-angiogenesis related RNAs, in part by differentially regulating their stability, to promote angiogenesis.

cell biology↗

Metaplasia Orchestrates Tissue Recovery and Immune Remodeling Through CD73 in Chronic Pancreatitis

Chronic inflammatory injury promotes epithelial metaplasia, and progression from metaplasia to dysplasia is a recognized initiating event in carcinogenesis, as metaplastic cells exhibit heightened susceptibility to genetic alterations. In the pancreas, persistent acinar-to-ductal metaplasia (ADM) can progress to pancreatic intraepithelial neoplasia (PanIN), yet the mechanisms that determine whether ADM resolves or persists with fibrosis and sustained inflammation remain poorly defined. Here, we identify CD73 as a central regulator of ADM fate, tissue repair, and immune microenvironment remodeling during chronic pancreatic injury. Analysis of previously published single-cell RNA sequencing dataset from chronic pancreatitis (CP) tissues identified enrichment of Nt5e, which encodes CD73, within Hnf1{beta} ADM populations. Hnf1bCreERT2 and CD73fl/fl;Hnf1bCreERT2 mice were treated with caerulein for 4 weeks to induce pancreatitis and ADM prior to tamoxifen-induced deletion of CD73 in HNF1B-expressing metaplastic epithelial cells. Histologic phenotyping and immune profiling were performed using immunohistochemistry and imaging mass cytometry. Metaplasia-specific CD73 deletion exacerbated pancreatic injury and fibrosis, impaired epithelial proliferation and recovery of the acinar compartment, and altered the abundance and spatial organization of inflammatory cells. Ex vivo ADM assays further demonstrated that CD73 loss increased ADM formation and the production of MCP-1 and TIMP-1. These findings identify CD73 as a context-dependent checkpoint linking epithelial plasticity and immune modulation during chronic pancreatic injury and tissue repair.

cell biology↗