A region of cell-cell adhesion at which the actin cytoskeleton is anchored to the plasma membrane.
armadillo protein family
A family of proteins, including β-catenin, that link cadherins to the cytoskeleton at stable cell-cell junctions.
auxin
A plant hormone that controls many aspects of plant development.
basal lamina
A sheetlike extracellular matrix that supports epithelial cells and surrounds muscle cells, adipose cells, and peripheral nerves.
cadherin
A cell adhesion molecule that forms stable cell-cell junctions at adherens junctions and desmosomes.
cell adhesion molecule
A transmembrane protein that mediates cell-cell interactions.
cellulose
The principal structural component of the plant cell wall, a linear polymer of glucose residues linked by β(1→4) glycosidic bonds.
cellulose synthase
An enzyme that catalyzes the synthesis of cellulose.
chitin
A polymer of N-acetylglucosamine residues that is the principal component of fungal cell walls.
collagen
The major structural protein of the extracellular matrix.
collagen fibril
A fibril formed by the assembly of collagen molecules in a regularly staggered array.
connexin
A member of a family of transmembrane proteins that form gap junctions.
connexon
A cylinder formed by six connexins in the plasma membrane.
desmocollin
A type of transmembrane cadherin that links intermediate filament cytoskeletons of adjacent cells at desmosomes.
desmoglein
A type of transmembrane cadherin that links intermediate filament cytoskeletons of adjacent cells at desmosomes.
desmosome
A region of contact between epithelial cells at which keratin filaments are anchored to the plasma membrane. See also hemidesmosome.
elastic fiber
A protein fiber present in the extracellular matrix of connective tissues in organs that stretch and then return to their original shape.
elastin
The principal component of elastic fibers.
electrical synapse
A specialized assembly of gap junctions that allows the rapid passage of ions between nerve cells.
entactin
An extracellular matrix protein that interacts with laminins and type IV collagen in basal laminae.
extracellular matrix
Secreted proteins and polysaccharides that fill spaces between cells and bind cells and tissues together.
fibronectin
The principal adhesion protein of the extracellular matrix.
focal adhesion
A site of attachment of cells to the extracellular matrix at which integrins are linked to bundles of actin filaments.
focal complex
A small cluster of integrins binding to the extracellular matrix that initiates the formation of a focal adhesion.
gap junction
A plasma membrane channel forming a direct cytoplasmic connection between adjacent cells.
glycosaminoglycan (GAG)
A gel-forming polysaccharide of the extracellular matrix.
hemicellulose
A polysaccharide that crosslinks cellulose microfibrils in plant cell walls.
hemidesmosome
A region of contact between cells and the extracellular matrix at which keratin filaments are attached to integrin.
heterophilic interaction
An interaction between two different types of cell adhesion molecules.
homophilic interaction
An interaction between cell adhesion molecules of the same type.
immunoglobulin (Ig) superfamily
A family of cell adhesion molecules containing structural domains similar to immunoglobulins.
integrin
A transmembrane protein that mediates the adhesion of cells to the extracellular matrix.
integrin
A transmembrane protein that mediates the adhesion of cells to the extracellular matrix.
junctional complex
A region of cell-cell contact containing a tight junction, an adherens junction, and a desmosome.
laminin
The principal adhesion protein of basal laminae.
lignin
A polymer of phenolic residues that strengthens secondary cell walls.
middle lamella
A region of the plant cell wall that acts as a glue to hold adjacent cells together.
nectin
A cell adhesion molecule involved in the formation of adherens junctions.
pectin
A gel-forming polysaccharide in plant cell walls.
peptidoglycan
The principal component of bacterial cell walls consisting of linear polysaccharide chains crosslinked by short peptides.
plakin
A member of a family of proteins that link intermediate filaments to other cellular structures.
plasmodesma
A cytoplasmic connection between adjacent plant cells formed by a continuous region of the plasma membrane.
primary cell wall
The wall of growing plant cells.
procollagen
Soluble precursor to the fibril-forming collagens.
proteoglycan
A protein linked to glycosaminoglycans.
secondary cell wall
A thick cell wall laid down between the plasma membrane and the primary cell wall of plant cells that have ceased growth.
selectin
A type of cell adhesion molecule that recognizes oligosaccharides exposed on the cell surface.
tight junction
A continuous network of protein strands around the circumference of epithelial cells, sealing the space between cells and forming a barrier between the apical and basolateral domains.
turgor pressure
The internal hydrostatic pressure within plant cells.
