Protein Transport


In order for cells to function, proteins are selectively sorted and precisely transported to their destinations after synthesis on ribosomes in the cytoplasm. Proteins contain signals for targeting and cells contain the appropriate machinery to allow the recognition of the signals and the targeting of each protein to its destination.

Keywords: targeting signal; nucelocytoplasmic transport; vesicular transport; organelle; membrane translocation

Figure 1.

Schematic views of the nuclear (a) import and (b) export of proteins. Cargo proteins are transported into and out of the nucleus by importin/karyopherin or exportin. A small GTPase Ran functions as a molecular switch for the shipping and discharging of cargoes. NPC: nuclear pore complex.

Figure 2.

Scheme for the protein traffic between the endoplasmic reticulum (ER) and Golgi apparatus. Cargo proteins in the ER are transported to the Golgi apparatus by the ER‐to‐Golgi anterograde transport system. Certain proteins are recycled back to the ER via the Golgi‐to‐ER retrograde transport system. ARF: adenosine diphosphate ribosylation factor; SNARE: soluble N‐ethylmaleimide‐sensitive fusion protein attachment protein receptor.



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Further Reading

Chook YM and Blobel G (2001) Karyopherins and nuclear import. Current Opinion in Structural Biology 11: 703–715.

Farquhar MG and Palade GE (1998) The Golgi apparatus: 100 years of progress and controversy. Trends in Cell Biology 8: 2–10.

Görlich D and Kutay U (1999) Transport between the cell nucleus and cytoplasm. Annual Reviews of Cell and Developmental Biology 15: 607–660.

Hettema EH, Distel B and Tabak HF (1999) Import of proteins into peroxisomes. Biochimica et Biophysica Acta 1451: 17–34.

Kuersten S, Ohno M and Mattaj IW (2001) Nucleocytoplasmic transport: Ran, beta and beyond. Trends in Cell Biology 11: 497–503.

Mihara K (2000) Targeting and insertion of nuclear‐encoded preproteins into the mitochondrial outer membrane. BioEssays 22: 364–371.

Pelham HRB (2001) SNAREs and the specificity of membrane fusion. Trends in Cell Biology 11: 99–101.

Rothman JE (1994) Mechanisms of intracellular protein transport. Nature 372: 55–63.

Yoneda Y (2000) Nucleocytoplasmic protein traffic and its significance to cell function. Genes to Cells 5: 777–787.

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How to Cite close
Yoneda, Yoshihiro(Jan 2006) Protein Transport. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0005720]