Cell Junctions

Cell junctions are subcellular macromolecular structures connecting cells to each other or to the extracellular matrix (ECM). Cell junctions include focal adhesions, tight junctions, gap junctions, adherens junctions, desmosomes, and hemidesmosomes. Each one plays a specific role in adhesion, communication, and transduction of mechanical force. Tight junctions seal adjacent epithelial cells together. Other adjacent cells communicate via cytosolic ions and small molecules through gap junctions. Focal adhesions and hemidesmosomes connect integrin–ECM contacts to actin and intermediate filaments. Cadherin cell–cell contacts are connected to actin and intermediate filaments by adherens junctions and desmosomes. Cell junctions regulate many normal biological processes, such as cell and metabolite transport across epithelial layers, development and differentiation programs, excitable cell contraction, immune responses, and neural activity. Destabilization of cell junction integrity and function via gene expression changes or gene mutations plays a key role in the pathophysiology of diseases such as cardiovascular disease, developmental abnormalities, epithelial-to-mesenchymal transition (cancer metastasis), inflammatory bowel disease, and neurological disorders. Although specific cell junctions predominate in certain cell types, all cells interact with their environment via more than one, or even all, of these junctions. Analyzing the expression, regulation, and sequence of cell junction genes can help determine their relative importance to the biology of the cellular or disease processes under study.

QIAGEN provides a broad range of assay technologies for cell junction research that enables analysis of gene expression and regulation, epigenetic modification, genotyping, and signal transduction pathway activation. Solutions optimized for cell junction studies include PCR array, miRNA, siRNA, mutation analysis, pathway reporter, chromatin IP, DNA methylation, and protein expression products.