Myosin Vb is required for trafficking of the cystic fibrosis transmembrane conductance regulator in Rab11a-specific apical recycling endosomes in polarized human airway epithelial cells.
Cystic fibrosis transmembrane conductance regulator (CFTR)-mediated Cl(-) secretion across fluid-transporting epithelia is regulated, in part, by modulating the number of CFTR Cl(-) channels in the plasma membrane by adjusting CFTR endocytosis and recycling. However, the mechanisms that regulate CFTR recycling in airway epithelial cells remain unknown, at least in part, because the recycling itineraries of CFTR in these cells are incompletely understood. In a previous study, we demonstrated that CFTR undergoes trafficking in Rab11a-specific apical recycling endosomes in human airway epithelial cells. Myosin Vb is a plus-end-directed, actin-based mechanoenzyme that facilitates protein trafficking in Rab11a-specific recycling vesicles in several cell model systems. There are no published studies examining the role of myosin Vb in airway epithelial cells. Thus, the goal of this study was to determine whether myosin Vb facilitates CFTR recycling in polarized human airway epithelial cells. Endogenous CFTR formed a complex with endogenous myosin Vb and Rab11a. Silencing myosin Vb by RNA-mediated interference decreased the expression of wild-type CFTR and DeltaF508-CFTR in the apical membrane and decreased CFTR-mediated Cl(-) secretion across polarized human airway epithelial cells. A recombinant tail domain fragment of myosin Vb attenuated the plasma membrane expression of CFTR by arresting CFTR recycling. The dominant-negative effect was dependent on the ability of the myosin Vb tail fragment to interact with Rab11a. Taken together, these data indicate that myosin Vb is required for CFTR recycling in Rab11a-specific apical recycling endosomes in polarized human airway epithelial cells.
Swiatecka-Urban
Agnieszka
A
Department of Physiology, Dartmouth Medical School, Dartmouth College, Hanover, New Hampshire 03755, USA.
Talebian
Laleh
L
Kanno
Eiko
E
Moreau-Marquis
Sophie
S
Coutermarsh
Bonita
B
Hansen
Karyn
K
Karlson
Katherine H
KH
Barnaby
Roxanna
R
Cheney
Richard E
RE
Langford
George M
GM
Fukuda
Mitsunori
M
Stanton
Bruce A
BA
D000595:Amino Acid Sequence; D002460:Cell Line; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology*; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D018995:Myosin Heavy Chains / Q000737:chemistry / Q000502:physiology*; D024701:Myosin Type V / Q000737:chemistry / Q000502:physiology*; D034622:RNA Interference; D014162:Transfection; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D018995:Myosin Heavy Chains; D024701:Myosin Type V; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C505032:CFTR protein, human; C505832:MYO5B protein, human