Adherens junctions 2. Focal adhesions 3. Gap junctions are composed of clusters of proteins that allow molecules smaller than 1kDa to pass directly from the inside of one cell to the inside of another.
Gap junctions mediate electrical and chemical coupling between cells.
The molecules that are found in ECM are usually produced by cells embedded in the matrix itself. Structural fibrous proteins include collagen and elastin . Adhesive glycoproteins include fibronectin and laminin . Integrins can link ECM proteins to the cytoplasm via actin filaments or intermediate filaments depending on the integrin type. Integrins are transmembrane heterodimers consisting of one a subunit and one b subunit.