Junctional Adhesion Molecule 1

Updated: 2026-09-13

Overview

Junctional Adhesion Molecule 1 (JAM1), encoded by the F11R gene, is a 40-kDa transmembrane glycoprotein predominantly expressed at tight junctions of endothelial and epithelial cells. It belongs to the immunoglobulin superfamily and features two extracellular Ig-like domains. JAM1 homodimerizes and heterodimerizes with other JAM family members (e.g., JAM2/JAM3) to regulate paracellular permeability. First identified in 1998, JAM1 has since been recognized as a multifunctional protein contributing to barrier maintenance, angiogenesis, and immune cell trafficking. Its cytoplasmic tail interacts with scaffold proteins like ZO-1 and AF-6, linking it to the actin cytoskeleton. These interactions make JAM1 a key player in maintaining tissue integrity during physiological and pathological processes.

Key Features

JAM1 exhibits dual functionality: structural (maintaining tight junctions) and signaling (modulating immune responses). Its extracellular domain binds ligands including LFA-1 on leukocytes, facilitating their transendothelial migration during inflammation. This interaction is exploited by pathogens like reoviruses, which use JAM1 as a receptor for cell entry. The protein's PDZ-binding motif enables recruitment of signaling molecules such as PAR-3 and Pals1, influencing cell polarity. JAM1 also regulates platelet activation via interactions with integrin αIIbβ3. These diverse roles stem from its ability to form cis- and trans-interactions, creating dynamic molecular networks at cell contacts.

Application Areas

In biomedical research, JAM1 antibodies and recombinant proteins are widely used to study vascular permeability in conditions like atherosclerosis and sepsis. Its role in leukocyte extravasation makes it a target for anti-inflammatory drug development, with blocking antibodies showing promise in animal models of multiple sclerosis. Cancer researchers investigate JAM1's involvement in metastasis, as its expression correlates with tumor progression in glioblastoma and breast cancer. Additionally, JAM1 serves as a biomarker for endothelial activation in preeclampsia and other vascular disorders. Emerging applications include engineered JAM1 fragments for modulating immune responses in autoimmune therapies.

Precautions

When working with JAM1 proteins or antibodies, maintain cold chain conditions (2-8°C for short-term storage; -80°C for long-term). Avoid repeated freeze-thaw cycles, which can cause protein aggregation. For cell-based assays, confirm the absence of endotoxins in recombinant proteins to prevent unintended immune activation. Researchers should validate antibody specificity using knockout controls, as some commercial antibodies may cross-react with other JAM family members. In vivo studies require careful dosage optimization of JAM1-targeting agents due to potential off-target effects on endothelial barrier function.

B2B Procurement Guide

Major suppliers include R&D Systems, Abcam, and Sino Biological, offering JAM1 products in various formats (recombinant proteins, antibodies, ELISA kits). Bulk orders (10+ mg) typically receive 15-30% discounts. Prioritize vendors providing Certificate of Analysis with detailed characterization data (HPLC purity, endotoxin levels, functional assays). For custom services like JAM1 mutant construction or labeling (biotin/FITC), expect 4-8 week lead times. Some CROs offer JAM1-related cell migration assay services at approximately $800-$1,500 per 96-well plate. When comparing quotes, consider additional costs for shipping frozen materials and import duties for international transactions.