What do integrins do in relation to cell membranes?

Integrins play a crucial role in the interaction between cells and their external environment, particularly in transmitting signals between the extracellular matrix (ECM) and the cytoskeleton. They are transmembrane proteins that connect the ECM outside the cell to the cytoskeleton inside the cell. When integrins bind to components in the ECM, they can activate intracellular signaling pathways that influence various cellular functions, including cell proliferation, survival, and migration.

This signaling capability is essential for maintaining tissue integrity and facilitating communication between cells and their surrounding matrix. It allows cells to respond to changes in their environment, thus playing a significant role in processes such as development, wound healing, and immune responses.

In contrast, the other options refer to functions that integrins do not perform. While integrins do indeed facilitate cell adhesion, this function is more about connecting cells to the ECM rather than signaling. Tight junctions involve different proteins that help in sealing cells together to prevent leakage; therefore, this is not a role of integrins. Storing energy in cells generally relates to organelles like mitochondria or structures like glycogen granules, which is unrelated to the function of integrins.