Question

The lateral movement of transmembrane proteins can be restricted by several different mechanisms. Which mechanism best describes the process by which neutrophils are recruited by endothelial cells?

1) proteins are tethered to the cell cortex
2) proteins are tethered to the extracellular matrix
3) proteins are tethered to the proteins on the surface of another cell
4) protein movement is limited by the presence of a diffusion barrier

Answer 1

Neutrophil recruitment by endothelial cells occurs via cell adhesion, where transmembrane proteins of endothelial cells bind to those on neutrophils, representing the mechanism wherein proteins are tethered to the proteins on the surface of another cell.

Step-by-step explanation:

Neutrophils are recruited by endothelial cells through a process called cell adhesion, which involves transmembrane proteins. These proteins on endothelial cells bind to proteins on the surface of neutrophils. This mechanism of recruitment aligns with the statement that proteins are tethered to the proteins on the surface of another cell. During this interaction, the lateral movement of transmembrane proteins can be restricted. Protein movement may also be limited by the presence of a diffusion barrier, which can include elements of the cytoskeleton, the extracellular matrix, or contact with other cells. However, in the specific context of neutrophil recruitment by endothelial cells, the tethering to another cell is the most applicable mechanism.