Integrins anchor cells to the scaffolding that surrounds them, while cadherins glue neighboring cells to one another. That single-sentence distinction captures the most fundamental difference between these two families of adhesion receptors, but the deeper you look, the more ways they diverge in structure, signaling, ion dependency, and disease relevance. They also turn out to be far more intertwined than their separate job descriptions suggest, sharing cytoskeletal connections and signaling partners that let them coordinate tissue behavior in ways researchers are still mapping out.
What Each One Actually Does
Integrins are the cell’s grip on its physical environment. They span the cell membrane and latch onto proteins in the extracellular matrix, the dense mesh of collagen, fibronectin, and other structural molecules that fills the space between cells. This binding is heterophilic, meaning each side of the connection is a different molecule. An integrin on the cell surface recognizes a specific sequence on a matrix protein, and a metal ion physically bridges the two together.
Cadherins handle a completely different job. They reach out from one cell’s surface and bind to a matching cadherin on the surface of a neighboring cell. This is homophilic adhesion: cadherin binds to cadherin of the same type. E-cadherin on one epithelial cell grabs E-cadherin on the cell next door, using a “strand exchange” mechanism where a short arm at the tip of one cadherin molecule docks into a pocket on its partner.1Elsevier. The crystal structure of human E-cadherin domains 1 and 2, and comparison with other cadherins in the context of adhesion mechanism This lock-and-key pairing between identical molecules is what makes cadherins the primary enforcers of cell-cell contact in tissues.
The practical upshot: integrins tell a cell where it sits in the tissue’s architecture, while cadherins tell a cell who its neighbors are. Both pieces of information are essential for building and maintaining organs, but they come through entirely separate receptor systems.
Structural Differences
Integrins are built from two different protein subunits, called alpha (α) and beta (β), that pair up to form a heterodimer. Humans have 18 α subunits and 8 β subunits, which mix and match to produce 24 known integrin combinations. Each combination recognizes a different set of matrix proteins, so the particular integrins a cell displays on its surface determine what it can stick to. The extracellular portion of the α subunit contains a propeller-shaped domain, while the β subunit has an I-like domain at its tip that does much of the ligand-binding work.2PubMed Central. The regulation of integrin function by divalent cations
Cadherins look nothing like this. A classical cadherin is a single-pass transmembrane protein, meaning one continuous polypeptide chain crosses the membrane once. Its extracellular portion is made of repeated domains (typically five in classical cadherins like E-cadherin and N-cadherin) arranged end to end like beads on a string. These domains are separated by rigid calcium-binding linker regions that keep the whole structure extended and slightly curved. The intracellular tail connects to a set of adaptor proteins, the catenins, which link the cadherin to the cell’s internal skeleton.
So structurally, you are comparing a two-part receptor with a modular, single-chain receptor. The integrin’s two subunits can undergo dramatic shape changes, bending and straightening to toggle between inactive and active states. Cadherins rely on subtler conformational shifts, particularly at that N-terminal “adhesion arm” whose open-versus-closed state primes the molecule for binding.1Elsevier. The crystal structure of human E-cadherin domains 1 and 2, and comparison with other cadherins in the context of adhesion mechanism
Different Metal Ions, Different Roles
Both integrins and cadherins depend on positively charged metal ions to function, but they use different metals and for different purposes. Integrins are sometimes described as metalloprotein receptors because divalent cations are woven into their structure at multiple critical sites. The most important is the MIDAS motif, a metal-ion-dependent adhesion site on the β subunit’s I-like domain that physically coordinates a magnesium or manganese ion to bridge the integrin to its ligand. Two flanking sites called ADMIDAS and SyMBS fine-tune integrin affinity and help relay signals across the membrane. The α subunit also carries three or four calcium-binding loops in its propeller domain that are required for the integrin to fold correctly during production.2PubMed Central. The regulation of integrin function by divalent cations
Cadherins, by contrast, are calcium specialists. The very name “cadherin” is shorthand for “calcium-dependent adhesion.” Calcium ions sit between each pair of extracellular domains and act like mortar between bricks, stiffening the molecule into an elongated rod. Remove calcium and the whole extracellular region collapses into a floppy, disordered shape. Simulations of C-cadherin show that without calcium the molecule switches from stiff and rod-like to soft and spring-like, and the conserved tryptophan residue responsible for docking into a neighboring cadherin flips from exposed to intermittently buried, effectively disabling adhesion.3Biophysical Journal. Calcium-Mediated Allostery and Mechanical Response of C-Cadherin
In practical terms, this means that both receptor families stop working if you strip away divalent cations with a chelating agent like EDTA, a trick cell biologists routinely exploit when they want to detach cultured cells from a dish or from each other. But the specific ions involved and the way they participate in the adhesion mechanism are distinct.
How They Link to the Cell’s Internal Skeleton
Both integrins and cadherins connect to the actin cytoskeleton, the network of protein filaments that gives a cell its shape and lets it move. Integrins do this through a cluster of adaptor proteins at focal adhesions, the anchor points where a cell grips the matrix. Cadherins do it through catenins at adherens junctions, where neighboring cells are held together. Both receptor families share some of the same signaling intermediaries, which is one reason their activities are so tightly coordinated.4PubMed Central. The mechanical regulation of integrin–cadherin crosstalk organizes cells, signaling and forces
Where they diverge is in their relationship with intermediate filaments, a separate class of tough, rope-like cytoskeletal fibers. In specialized junctions called desmosomes, cadherin-family members (desmosomal cadherins, specifically desmogleins and desmocollins) link to intermediate filaments like keratin, providing the extreme mechanical resilience that skin and heart muscle need. The integrin equivalent is the hemidesmosome, found where epithelial cells attach to the underlying basement membrane. Hemidesmosomes also connect to intermediate filaments but through integrin receptors rather than cadherins.5PubMed. Desmosomes and hemidesmosomes: structure and function of molecular components So while both families can hook into intermediate filaments, they do so at entirely different locations: cadherins at cell-cell borders, integrins at the cell-matrix interface.6Current Biology. Tracing the Evolutionary Origin of Desmosomes
How They Coordinate With Each Other
Despite having separate jobs, integrins and cadherins do not operate in isolation. Crosstalk between the two systems turns out to be essential for tissue formation and collective cell movement. This coordination can happen through shared signaling proteins, through physical connections via the actin cytoskeleton, or through direct signaling pathways that link the two adhesion systems.7PubMed. Crosstalk between different adhesion molecules
One well-studied example involves N-cadherin junctions. Complexes of N-cadherin with different intracellular partners can suppress or enhance local signaling molecules like PI3K and myosin II, creating regions of high and low tension within the cell. N-cadherin-containing adherens junctions can also exclude certain integrins from their vicinity and block integrin activation nearby, effectively carving the cell surface into zones with distinct adhesive and mechanical properties.8Journal of Cell Science. The mechanical regulation of integrin–cadherin crosstalk organizes cells, signaling and forces
This interplay matters most during collective cell migration, when sheets of cells need to move together without falling apart. The balance between traction forces at integrin-based focal adhesions and tension at cadherin-based cell-cell junctions determines whether a group of cells advances as a coordinated unit or scatters. Differences in the extracellular matrix can even alter how much force is transmitted through cadherin junctions, with specific integrin types acting as the intermediaries that relay matrix stiffness to cell-cell contacts.9PubMed Central. Extracellular matrix regulates force transduction at VE-cadherin junctions
The Cadherin Switch in Cancer
One of the most clinically significant behaviors involving cadherins is the epithelial-to-mesenchymal transition, or EMT. In healthy epithelial tissues, cells display E-cadherin on their surfaces, keeping them tightly bonded to their neighbors. During EMT, cells downregulate E-cadherin and upregulate N-cadherin instead. This swap loosens cell-cell adhesion and enables cells to become migratory and invasive. The process is normal during embryonic development, but when it reactivates in adult tissues, it can drive cancer metastasis, drug resistance, and the emergence of tumor stem cells.10PubMed Central. The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges
Integrins play a supporting role during EMT. As cadherin-containing cell-cell contacts are disrupted, integrin-dependent motility ramps up. The endocytic recycling pathways that shuttle cadherins and integrins to and from the cell surface appear to help coordinate this transition, with E-cadherin recycling slowing down while integrin recycling speeds up to supply the newly motile cell with the adhesion receptors it needs for migration.11Current Opinion in Cell Biology. Endocytic recycling pathways: emerging regulators of cell migration A single ion channel called TRPML1 has been shown to regulate the intracellular trafficking of both E-cadherin and β1-integrin, and knocking it out reduces a cancer cell’s ability to migrate and adhere.12PubMed Central. Endolysosomal TRPML1 channel regulates cancer cell migration by altering intracellular trafficking of E-cadherin and β(1)-integrin
Diseases Linked to Each Family
Genetic defects in integrins and cadherins lead to very different clinical pictures, reflecting the distinct biological roles of each receptor family.
For integrins, the textbook example is leukocyte adhesion deficiency type 1, or LAD-1. This condition is caused by mutations in the gene encoding the β2 integrin subunit. Without functional β2 integrins, white blood cells cannot stick to blood vessel walls or migrate into infected tissues. The syndrome often shows up right at birth with delayed separation of the umbilical cord, and affected children suffer severe, recurring infections because their immune cells simply cannot get where they need to go.13PubMed Central. Hematologically important mutations: leukocyte adhesion deficiency (first update) Studies of patient mutations show that the majority of the single amino-acid substitutions found in LAD-1 prevent the integrin from reaching the cell surface at all.14PubMed. Characterization of single amino acid substitutions in the β2 integrin subunit of patients with leukocyte adhesion deficiency (LAD)-1
For cadherins, the clearest genetic disease link is hereditary diffuse gastric cancer. Germline mutations in the CDH1 gene, which encodes E-cadherin, account for roughly 30% of families with this cancer syndrome. Carriers face a lifetime risk of around 80% for diffuse gastric cancer and around 60% for lobular breast cancer.15PubMed Central. Hereditary diffuse gastric cancer associated with E-cadherin germline mutation: a case report A systematic review found that among patients diagnosed with diffuse gastric cancer in studied families, the vast majority carried a positive germline E-cadherin mutation, and every mutation carrier examined showed microscopic evidence of signet ring cell cancer in the stomach lining.16PubMed Central. Significance of E-cadherin Gene Mutations in Patients With Hereditary Diffuse Gastric Cancer Syndrome: A Systematic Review Because of this near-certainty that cancer will develop, international guidelines now recommend prophylactic total gastrectomy for confirmed CDH1 mutation carriers.
The contrast is instructive. Integrin defects tend to disrupt immune cell trafficking and wound healing, areas where cell-matrix adhesion is paramount. Cadherin defects tend to disrupt tissue integrity and cell growth control, reflecting cadherins’ role in maintaining the orderly architecture of epithelial sheets.
How Pathogens Exploit These Receptors
Bacteria and viruses have evolved to hijack both integrins and cadherins as entry points into host cells, but the strategies differ. Many bacterial pathogens produce surface proteins called adhesins that bind directly or indirectly to integrins on lung, gut, or skin epithelial cells, effectively using the cell’s own adhesion machinery as a doorway.17PubMed Central. The role of epithelial integrin receptors in recognition of pulmonary pathogens Some viruses also target integrins; certain adenoviruses, for instance, bind an RGD-recognizing integrin to trigger their own internalization.
Cadherins are exploited differently. Because cadherins mediate tight cell-cell junctions, some pathogens target them not to enter individual cells but to pry open the junctions between cells and slip through the epithelial barrier. Bacteria like Listeria monocytogenes bind directly to E-cadherin to gain access to host tissues. The shared theme is that pathogens have learned to treat cell adhesion receptors as both locks and hinges, using integrins and cadherins to trigger signaling events that rearrange the host cell’s cytoskeleton in the pathogen’s favor.18PubMed. Cell adhesion receptors – signaling capacity and exploitation by bacterial pathogens
Evolutionary Origins
Given how different integrins and cadherins are in structure and function, it is not surprising that they have separate evolutionary histories. Integrin components turn out to be older than anyone expected. Core parts of the integrin adhesion machinery have been found in the genome of an obscure single-celled organism called Amastigomonas, a protist that diverged from the lineage leading to animals and fungi long before multicellular life appeared. This means the basic toolkit for integrin-mediated adhesion predates animal multicellularity by a wide margin.19PubMed Central. Ancient origin of the integrin-mediated adhesion and signaling machinery
Cadherins have a different but equally surprising backstory. Diverse cadherin genes have been found in choanoflagellates, the closest single-celled relatives of animals. These organisms carry cadherin gene numbers comparable to those in complex animals, even though choanoflagellates are not multicellular in the conventional sense. The discovery suggests that cadherins were already diversifying before multicellularity evolved and may have been among the molecular tools that made the leap to animal-style tissues possible in the first place.20PubMed. The premetazoan ancestry of cadherins
So both families were present in single-celled ancestors, but likely serving different primordial functions. Integrins may have originally helped cells interact with their physical substrate, while cadherins may have facilitated the transient cell-cell contacts that eventually became permanent in animal tissues.
Applications in Biomaterials and Tissue Engineering
Understanding the differences between integrins and cadherins has become directly relevant to designing synthetic materials for medicine. Most tissue-engineering scaffolds have historically been built to engage integrins, since cells need matrix-like cues to attach, spread, and survive on an artificial surface. Short peptide sequences that mimic integrin-binding sites on natural matrix proteins are now routinely grafted onto biomaterials. Researchers have demonstrated the ability to target a wide range of specific integrin pairs with synthetic peptides, allowing them to fine-tune which biological responses the material triggers, from cell spreading to differentiation to migration.21PubMed Central. Review of Integrin-targeting Biomaterials in Tissue Engineering
More recently, biomaterials that mimic cadherin-based cell-cell interactions have started to appear. The logic is that for tissues like epithelium, cartilage, or cardiac muscle, cells need both matrix cues and neighbor cues to organize properly. Materials that present cadherin-mimetic ligands alongside integrin-binding peptides can recreate something closer to the full adhesive environment a cell experiences in a living tissue. This dual-cue approach is an active area of research in regenerative medicine, with early applications in studying fundamental cell biology and in engineering replacement tissues.22PubMed. You Talking to Me? Cadherin and Integrin Crosstalk in Biomaterial Design
How Cells Recycle These Receptors
Neither integrins nor cadherins sit permanently on the cell surface. Both are continuously pulled inside the cell through endocytosis, sorted through internal compartments, and either sent back to the surface or directed to degradation. This recycling is not just housekeeping; it is a way the cell actively controls how sticky it is and in which direction it moves.
For integrins, endosomal recycling is tightly linked to the turnover of focal adhesions. As a migrating cell extends forward, integrins are delivered to the leading edge from internal stores. At the trailing edge, focal adhesions disassemble and integrins are internalized. The endosomal pathways do not just move integrins around; they also supply factors needed to take focal adhesions apart, making the recycling machinery an active participant in migration rather than a passive shuttle.23PubMed Central. On the move: endocytic trafficking in cell migration
Cadherin recycling works differently. In stable epithelial sheets, E-cadherin cycles through a rapid “short-loop” pathway that quickly returns it to the cell surface, helping maintain steady cell-cell contact. When conditions change and a cell needs to break free from its neighbors, the balance shifts: E-cadherin is routed toward degradation instead of recycling, and its loss from the surface loosens cell-cell junctions. The fact that a single trafficking regulator like TRPML1 can affect both E-cadherin and β1-integrin recycling, yet do so through different mechanisms depending on cell type, underscores how finely cells tune these two adhesion systems even at the level of internal membrane traffic.12PubMed Central. Endolysosomal TRPML1 channel regulates cancer cell migration by altering intracellular trafficking of E-cadherin and β(1)-integrin