Figure 12-6. A simplified “roadmap” of protein traffic.

Figure 12-6A simplified “roadmap” of protein traffic

Proteins can move from one compartment to another by gated transport (red), transmembrane transport (blue), or vesicular transport (green). The signals that direct a given protein's movement through the system, and thereby determine its eventual location in the cell, are contained in each protein's amino acid sequence. The journey begins with the synthesis of a protein on a ribosome in the cytosol and terminates when the final destination is reached. At each intermediate station (boxes), a decision is made as to whether the protein is to be retained in that compartment or transported further. In principle, a signal could be required for either retention in or exit from a compartment. We shall use this figure repeatedly as a guide throughout this chapter and the next, highlighting in color the particular pathway being discussed.

From: The Compartmentalization of Cells

Cover of Molecular Biology of the Cell
Molecular Biology of the Cell. 4th edition.
Alberts B, Johnson A, Lewis J, et al.
New York: Garland Science; 2002.
Copyright © 2002, Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter; Copyright © 1983, 1989, 1994, Bruce Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts, and James D. Watson .

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.