Protein

Functions

Reference

Tight junctions

Junctional adhesion molecule (JAM)

JAMs play a minor role in regulating junctional structure. Their main function is to promote adhesion and transmit intercellular signals [67].

JAM structure [68-70]

Claudine

Generation of TJ filaments, the structural and functional core of TJ in the plasma membrane [71].

Claudine  structure [72-74]  

Occludine

Auxiliary function in TJ formation [75]. Barrier function of TJ and intercellular adhesive interactions [76-78]. Transmissive properties due to binding to tyrosine kinase c-Yes, atypical protein kinase C (aPKC) and phosphoinositide 3-kinase (PI3K), protein phosphatase 2A [79-80].

Occludine structure [81-82]

Tricelluline

Regulation of macromolecular flux and TJ organization. Maintenance of the structure of three-cell and two-cell contacts [83-84].

Tricelluline structure [85-86]

Zonula occludens (ZO)

Formation of TJs in epithelial cells [87]. They participate in the sequential stages of AJ and TJ assembly, as well as in their physical segregation in the membrane [88-90].

ZO structure [91-93]

Gap junctions

Connexon

Providing direct communication between cells, whereby small molecules are able to penetrate into the cytoplasm of neighboring cells [94].

Connexon structure [95-102]

Desmosome

Cytoplasmic protein plaque

They influence signaling pathways and potentially contribute to disease progression through mechanisms such as stimulating protein aggregation in conditions such as microglial activation. They perform functions of structural support and intercellular interaction [103].

Cytoplasmic protein plaque structure [104]

Keratine filaments

Mechanical support and tissue integrity of epithelial cells. Coordination of tissue spreading by balancing forces within the tissue. Cell migration, differentiation, and resistance to chemical stress and apoptosis [105].

Keratine filaments

structure [106]

Plakophilin

Regulation of cell adhesion, signaling pathways, metabolism, ciliary function, and intercellular junction dynamics. Plakophilin-2 coordinates energy metabolism and cardiomyocyte contractility, as well as modulates intestinal barrier function. Plakophilin-3 is involved in basal body docking in multiciliated cells, while plakophilin-4 and p120 catenin promote the formation of lateral adhesive junctions [107]

Plakophilin structure [108-109]

Desmocolin

Functions of cellular adhesion, forming desmosomes to maintain tissue integrity and strength, especially in the epithelium and cardiac muscle. Linking the cell membrane to intracellular intermediate filaments, providing structural support during mechanical stress. Restoration of the intestinal mucosa and influence on cell migration [110].

Desmocolin  structure [111]

Desmoglein

Cohesion and functioning of cardiomyocytes (cardiac muscle cells), epithelial differentiation and maintenance of tissue barrier integrity [112].

Desmoglein  structure [112]

Desmoplakin

Maintains tissue integrity, regulates cell differentiation and migration, and participates in myocardial development. It regulates the expression of genes responsible for electrical conductivity in the heart and is involved in processes such as wound healing and neurogenesis [113].

Desmoplakin  structure [114]

Adherens junctions

E-cadgerin

Maintenance of epithelial hemostasis. Participation in immune reactions [115].

E-cadgerin structure [116]

Nectine

Establishment of cellular polarity and connections, control of cell proliferation and movement, regulation of immune responses and participation in the development and maintenance of tissues [117].

Nectine structure [118]