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

Georg F Vogel; Katharina M C Klee; Andreas R Janecke; Thomas Müller; Michael W Hess; Lukas A Huber

doi:10.1083/jcb.201506112

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

J Cell Biol. 2015 Nov 9;211(3):587-604. doi: 10.1083/jcb.201506112.

Authors

Georg F Vogel¹, Katharina M C Klee², Andreas R Janecke³, Thomas Müller³, Michael W Hess⁴, Lukas A Huber⁵

Affiliations

¹ Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria Division of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
² Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria Institute of Molecular Biology, University of Innsbruck, 6020 Innsbruck, Austria Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria.
³ Department of Paediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria.
⁴ Division of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria lukas.a.huber@i-med.ac.at michael.hess@i-med.ac.at.
⁵ Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria lukas.a.huber@i-med.ac.at michael.hess@i-med.ac.at.

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Caco-2 Cells
Cell Line
Cell Line, Tumor
Cell Membrane / metabolism
Cell Polarity / physiology
Cystic Fibrosis Transmembrane Conductance Regulator / metabolism
Epithelial Cells / metabolism*
Epithelial Cells / physiology*
Exocytosis / physiology*
Glucose Transporter Type 5 / metabolism
HEK293 Cells
Humans
Malabsorption Syndromes / metabolism
Microvilli / metabolism
Microvilli / 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

Substances

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

Supplementary concepts

Microvillus inclusion disease