Cargo-selective apical exocytosis in epithelial cells is conducted by Myo5B, Slp4a, Vamp7, and Syntaxin 3.

Abstract

Mutations in the motor protein Myosin Vb (Myo5B) or the soluble NSF attachment protein receptor Syntaxin 3 (Stx3) disturb epithelial polarity and cause microvillus inclusion disease (MVID), a lethal hereditary enteropathy affecting neonates. To understand the molecular mechanism of Myo5B and Stx3 interplay, we used genome editing to introduce a defined Myo5B patient mutation in a human epithelial cell line. Our results demonstrate a selective role of Myo5B and Stx3 for apical cargo exocytosis in polarized epithelial cells. Apical exocytosis of NHE3, CFTR (cystic fibrosis transmembrane conductance regulator), and GLUT5 required an interaction cascade of Rab11, Myo5B, Slp4a, Munc18-2, and Vamp7 with Stx3, which cooperate in the final steps of this selective apical traffic pathway. The brush border enzymes DPPIV and sucrase-isomaltase still correctly localize at the apical plasma membrane independent of this pathway. Hence, our work demonstrates how Myo5B, Stx3, Slp4a, Vamp7, Munc18-2, and Rab8/11 cooperate during selective apical cargo trafficking and exocytosis in epithelial cells and thereby provides further insight into MVID pathophysiology.

• Authors: Georg F Vogel, Katharina M C Klee, Andreas R Janecke, Thomas Müller, Michael W Hess, Lukas A Huber
• Journal: The Journal of cell biology (J Cell Biol) Vol. 211 Issue 3 Pg. 587-604 (Nov 09 2015) ISSN: 1540-8140 [Electronic] United States
• PMID: 26553929 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 Vogel et al.

Chemical References

• Glucose Transporter Type 5
• MYO5B protein, human
• Munc18 Proteins
• Qa-SNARE Proteins
• R-SNARE Proteins
• SLC2A5 protein, human
• SLC9A3 protein, human
• SYTL4 protein, human
• Sodium-Hydrogen Exchanger 3
• Sodium-Hydrogen Exchangers
• VAMP7 protein, human
• Vesicular Transport Proteins
• Cystic Fibrosis Transmembrane Conductance Regulator
• Myosin Type V
• rab11 protein
• Myosin Heavy Chains
• rab GTP-Binding Proteins

Topics

• Caco-2 Cells
• Cell Line
• Cell Line, Tumor
• Cell Membrane (metabolism)
• Cell Polarity (physiology)
• Cystic Fibrosis Transmembrane Conductance Regulator (metabolism)
• Epithelial Cells (metabolism, physiology)
• Exocytosis (physiology)
• Glucose Transporter Type 5 (metabolism)
• HEK293 Cells
• Humans
• Malabsorption Syndromes (metabolism)
• Microvilli (metabolism, pathology)
• Mucolipidoses (metabolism)
• Munc18 Proteins (metabolism)
• Mutation (physiology)
• Myosin Heavy Chains (metabolism)
• Myosin Type V (metabolism)
• Qa-SNARE Proteins (metabolism)
• R-SNARE Proteins (metabolism)
• Signal Transduction (physiology)
• Sodium-Hydrogen Exchanger 3
• Sodium-Hydrogen Exchangers (metabolism)
• Vesicular Transport Proteins (metabolism)
• rab GTP-Binding Proteins (metabolism)