F2R

F2R Full Name

coagulation factor II (thrombin) receptor

F2R Introduction

F2R, also known as protease-activated receptor 1 (PAR-1), is a prototypical G protein–coupled receptor that addresses a core challenge in cardiovascular and inflammatory research: how extracellular proteolytic cues are translated into rapid and highly specific intracellular signaling events. Activated primarily by thrombin through a unique proteolytic cleavage mechanism, F2R reveals a tethered ligand that self-activates the receptor, triggering immediate signal transduction. This distinctive mode of activation distinguishes F2R from conventional ligand-binding receptors and makes it a critical molecular switch at the interface of coagulation and cellular communication. Widely expressed in platelets, endothelial cells, and various tumor cells, F2R functions as a central signaling node that integrates hemostatic, inflammatory, and proliferative pathways, making it highly relevant for researchers seeking to understand complex disease mechanisms.

Functionally, F2R is best known for its dominant role in platelet activation and thrombus formation, processes that are essential for maintaining vascular integrity but can become pathological when dysregulated. Upon activation, F2R couples to multiple G proteins, including Gαq, Gα12/13, and Gαi, initiating downstream signaling cascades such as MAPK/ERK and PI3K/AKT. These pathways drive cytoskeletal reorganization, platelet shape change, granule secretion, and integrin activation, ultimately leading to platelet aggregation. F2R is particularly sensitive to low concentrations of thrombin and acts as an early responder in platelet activation, working in coordination with other receptors to fine-tune the balance between normal hemostasis and excessive clot formation. Beyond platelets, F2R also regulates endothelial barrier function, leukocyte recruitment, angiogenesis, and cell migration, highlighting its broader role in vascular biology and inflammatory responses.

In the context of disease, aberrant F2R signaling is closely associated with thrombosis, cardiovascular disorders, cancer progression, and chronic inflammation. Overactivation of F2R can promote excessive platelet aggregation and thrombus formation, increasing the risk of conditions such as myocardial infarction and stroke. In cancer, elevated F2R expression has been linked to enhanced tumor cell proliferation, invasion, angiogenesis, and metastasis, making it a key contributor to tumor progression and an attractive therapeutic target. Additionally, genetic variations in the F2R gene can influence individual responses to antiplatelet therapies, highlighting its importance in personalized medicine. As a result, F2R has emerged as both a biomarker and a drug target, with ongoing efforts focused on developing selective inhibitors that can effectively reduce thrombotic risk while minimizing adverse effects, addressing a critical unmet need in both cardiovascular and oncology research.

Alternate Names for F2R

F2R; coagulation factor II (thrombin) receptor; TR; HTR; CF2R; PAR1; PAR-1; proteinase-activated receptor 1; protease-activated receptor 1; N2-11

• 1.Khetan R, et al.; Protease-Activated Receptor F2R Is a Potential Target for New Diagnostic/Prognostic and Treatment Applications for Patients with Ovarian Cancer. Int J Mol Sci. 2025, 26(17):8529.
  2.Houlahan CB, et al.; Analysis of the Healthy Platelet Proteome Identifies a New Form of Domain-Specific O-Fucosylation. Mol Cell Proteomics. 2024, 23(2):100717.