Mediated transport

GLUT1 is a transmembrane protein, which means it spans the entire width of the cell membrane, connecting the extracellular and intracellular region.

For instance, studies show that in the absence of a fully functional PRAP1 protein, MTTP fails to transport specific lipoproteins across the endoplasmic reticulum membrane.

The main function of these transport proteins is to facilitate the passage of molecules from the endoplasmic reticulum to the golgi apparatus, and vice versa.

[10] Due to the fact that type I collagen is the main ingredient of connective tissue, such mutations are the cause of numerous severe skeletal disorders such as osteogenesis imperfecta and cranio-lenticulo-sutural dysplasia.

This example highlights the importance of transport proteins, not only as a means for the passage of specific molecules across a membrane, but for proper bodily development.