Which proteins are involved in binding cells to other cells or the extracellular matrix?

Cell adhesion molecules (CAM) play a crucial role in binding cells to each other and to the extracellular matrix (ECM). These proteins are embedded in the cell membrane and facilitate a variety of interactions that are essential for maintaining tissue structure and function. They are responsible for cell recognition, signaling, and the mechanical linkage between cells, which is necessary for processes such as tissue repair, immune response, and development.

Cell adhesion molecules include different types, such as cadherins, integrins, selectins, and immunoglobulin superfamily members, each with specific functions and binding partners. By connecting cells to the ECM or to other cells, CAMs help to form stable tissue arrangements and physical barriers, which are vital for the organism's overall integrity.

In contrast, receptor proteins are primarily involved in receiving and transmitting signals from the extracellular environment into the cell, rather than in cell-to-cell or cell-to-matrix adhesion. Signal transduction proteins are typically focused on relaying signals within pathways after a receptor has been activated, while transport proteins are involved in moving substances across cell membranes. Consequently, despite the importance of these proteins, they do not function directly in the binding of cells as CAMs do.