The apical compartment: trafficking pathways, regulators and scaffolding proteins.
Defects in the trafficking of apical membrane proteins in polarized epithelial cells are often associated with diseases, including cystic fibrosis, Liddle's syndrome, nephrogenic diabetes insipidus and Dubin-Johnson syndrome. In recent years, we have learned much about the specialized apical trafficking pathways in polarized cells. Many laboratories have identified signals that direct proteins within these pathways and have defined protein interactions that mediate specific steps in the sorting and stabilization of these proteins. In addition, many cytosolic proteins, including lipid kinases, GTPases, ATPases and scaffolding/adaptor proteins that lack enzymatic activity, regulate the trafficking of proteins through these pathways. Recent advances in the field include the role of small GTPases, unconventional myosins and lipid kinases in apical endocytosis and transcytosis, and the identification of PDZ proteins that regulate apical membrane trafficking of receptors, transporters and ion channels.
Altschuler
Yoram
Y
Department of Pharmacology, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Ein Kerem Campus, 91120, Jerusalem, Israel. yoram11@md2.huji.ac.il
Hodson
Caleb
C
Milgram
Sharon L
SL
D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism*; D000818:Animals; D002451:Cell Compartmentation / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity / Q000502:physiology; D003600:Cytosol / Q000201:enzymology; D004847:Epithelial Cells / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006801:Humans; D021381:Protein Transport / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology
D033942:Adaptor Proteins, Vesicular Transport; D020558:GTP Phosphohydrolases