Secretory pathway

Cell biology

Secretory protein

Biology

Cytosol

Endocrinology

Extracellular

Biochemistry

Endoplasmic reticulum

Secretion

Transport protein

Galectin

Enzyme

Golgi apparatus

Seminars in Cell and Developmental Biology

Eukaryotic cells have a highly evolved system of protein secretion, and dysfunction in this pathway is associated with many diseases including cancer, infection, metabolic disease and neurological disorders. Most proteins are secreted using the conventional endoplasmic reticulum (ER)/Golgi network and as such, this pathway is well-characterised. However, several cytosolic proteins have now been documented as secreted by unconventional transport pathways. This review focuses on two of these proteins families: annexins and galectins. The extracellular functions of these proteins are well documented, as are associations of their perturbed secretion with several diseases. However, the mechanisms and regulation of their secretion remain poorly characterised, and are discussed in this review. This review is part of a Special Issues of SCDB on 'unconventional protein secretion' edited by Walter Nickel and Catherine Rabouille.

Unconventional secretion of annexins and galectins