Glycosaminoglycans: Sorting determinants in intracellular protein traffic.
Intracellular transport of proteins to their appropriate destinations is crucial for the maintenance of cellular integrity and function. Sorting information is contained either directly in the amino acid sequence or in a protein's post-translational modifications. Glycosaminoglycans (GAGs) are characteristic modifications of proteoglycans. GAGs are long unbranched polysaccharide chains with unique structural and functional properties also contributing to protein sorting in various ways. By deletion or insertion of GAG attachment sites it has been shown that GAGs affect polarized sorting in epithelial cells, targeting to and storage in secretory granules, and endocytosis. Most recently, the role of GAGs as signals for rapid trans-Golgi-to-cell surface transport, dominant over the cytosolic sorting motifs in the core protein, was demonstrated. Here, we provide an overview on existing data on the roles of GAGs on protein and proteoglycan trafficking.
Biozentrum, University of Basel, Basel, Switzerland. Electronic address: deyan.mihov@unibas.ch.
Deyan
D
Mihov
Biozentrum, University of Basel, Basel, Switzerland.
Martin
M
Spiess
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D004705:Endocytosis; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism* / Q000648:ultrastructure; D006025:Glycosaminoglycans / Q000737:chemistry / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D011509:Proteoglycans / Q000737:chemistry / Q000378:metabolism*; D022142:Secretory Vesicles / Q000378:metabolism
D006025:Glycosaminoglycans; D011509:Proteoglycans
Endocytosis; Glycosaminoglycans; Protein transport; Proteoglycans; TGN export