Unconventional Protein Secretion in Animal Cells.
All eukaryotic cells secrete a range of proteins in a constitutive or regulated manner through the conventional or canonical exocytic/secretory pathway characterized by vesicular traffic from the endoplasmic reticulum, through the Golgi apparatus, and towards the plasma membrane. However, a number of proteins are secreted in an unconventional manner, which are insensitive to inhibitors of conventional exocytosis and use a route that bypasses the Golgi apparatus. These include cytosolic proteins such as fibroblast growth factor 2 (FGF2) and interleukin-1β (IL-1β), and membrane proteins that are known to also traverse to the plasma membrane by a conventional process of exocytosis, such as α integrin and the cystic fibrosis transmembrane conductor (CFTR). Mechanisms underlying unconventional protein secretion (UPS) are actively being analyzed and deciphered, and these range from an unusual form of plasma membrane translocation to vesicular processes involving the generation of exosomes and other extracellular microvesicles. In this chapter, we provide an overview on what is currently known about UPS in animal cells.
Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore, 117597, Singapore.
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Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore, 117597, Singapore. bchtbl@nus.edu.sg.|NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore. bchtbl@nus.edu.sg.
Bor Luen
BL
Tang
D000818:Animals; D001343:Autophagy; D015415:Biomarkers; D002352:Carrier Proteins; D002462:Cell Membrane / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D055354:Exosomes / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D011506:Proteins / Q000378:metabolism*; D055571:Secretory Pathway; D022161:Transport Vesicles / Q000378:metabolism; D015003:Yeasts / Q000378:metabolism
D015415:Biomarkers; D002352:Carrier Proteins; D011506:Proteins
Animal cells; Autophagy; Exosomes; GRASP; Unconventional protein secretion (UPS)