title: Trafficking Ion Transporters to the Apical Membrane of Polarized Intestinal Enterocytes.
abstract: Epithelial cells lining the gastrointestinal tract require distinct apical and basolateral domains to function properly. Trafficking and insertion of enzymes and transporters into the apical brush border of intestinal epithelial cells is essential for effective digestion and absorption of nutrients. Specific critical ion transporters are delivered to the apical brush border to facilitate fluid and electrolyte uptake. Maintenance of these apical transporters requires both targeted delivery and regulated membrane recycling. Examination of altered apical trafficking in patients with Microvillus Inclusion disease caused by inactivating mutations in MYO5B has led to insights into the regulation of apical trafficking by elements of the apical recycling system. Modeling of MYO5B loss in cell culture and animal models has led to recognition of Rab11a and Rab8a as critical regulators of apical brush border function. All of these studies show the importance of apical membrane trafficking dynamics in maintenance of polarized epithelial cell function.
authors.affiliation: Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232.|Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232.
authors.forename: Amy Christine
authors.initials: AC
authors.lastname: Engevik
authors.affiliation: Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232.|Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232.|Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee 37232.|Nashville VA Medical Center, Nashville, Tennessee 37232.
authors.forename: James R
authors.initials: JR
authors.lastname: Goldenring
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000502:physiology; D020895:Enterocytes / Q000378:metabolism*; D006801:Humans; D017136:Ion Transport; D008286:Malabsorption Syndromes / Q000209:etiology; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008871:Microvilli / Q000473:pathology / Q000502:physiology; D009081:Mucolipidoses / Q000209:etiology; D018995:Myosin Heavy Chains / Q000378:metabolism; D024701:Myosin Type V / Q000378:metabolism; D021381:Protein Transport; D000074083:Sodium-Hydrogen Exchanger 3 / Q000378:metabolism; D000099149:Ezrin
chemical_list: D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D003598:Cytoskeletal Proteins; D026901:Membrane Transport Proteins; D018995:Myosin Heavy Chains; D024701:Myosin Type V; D000074083:Sodium-Hydrogen Exchanger 3; D000099149:Ezrin; C505832:MYO5B protein, human; C000613385:SLC9A3 protein, human