Forms of intracellular signalling: Contact-dependent
Contact-dependent intracellular signaling is a form of cell signaling that occurs through direct physical contact between cells. In humans, there are several types of contact-dependent signaling that play important roles in development, immunity, and disease:
- Notch signaling: Notch signaling is a highly conserved pathway that plays a critical role in cell fate determination during development. Notch receptors on one cell bind to ligands on an adjacent cell, leading to the cleavage and release of the intracellular domain of the Notch receptor. This intracellular domain can then enter the nucleus and regulate gene expression.
- E-cadherin signaling: E-cadherin is a transmembrane protein that mediates cell-cell adhesion in epithelial tissues. Binding of E-cadherin on one cell to E-cadherin on an adjacent cell can activate downstream signaling events that regulate cell proliferation, migration, and survival.
- Integrin signaling: Integrins are transmembrane receptors that mediate cell adhesion to the extracellular matrix. Binding of integrins to extracellular matrix proteins can activate downstream signaling events that regulate cell proliferation, migration, and survival.
- Immunological synapse: The immunological synapse is a specialized contact-dependent signaling pathway that allows T cells to recognize and respond to antigen-presenting cells. Binding of the T cell receptor to the antigen on the antigen-presenting cell can trigger downstream signaling events that activate the T cell and promote immune responses.
Overall, contact-dependent intracellular signaling is a critical mechanism for coordinating cell behavior and regulating cellular processes in humans. Dysregulation of these signaling pathways can lead to a variety of diseases, including cancer, autoimmune disorders, and developmental abnormalities. Understanding the mechanisms of contact-dependent signaling is an important area of research for developing new therapies for these diseases.