Receptor activation alters inner surface potential during phagocytosis.
The surface potential of biological membranes varies according to their lipid composition. We devised genetically encoded probes to assess surface potential in intact cells. These probes revealed marked, localized alterations in the charge of the inner surface of the plasma membrane of macrophages during the course of phagocytosis. Hydrolysis of phosphoinositides and displacement of phosphatidylserine accounted for the change in surface potential at the phagosomal cup. Signaling molecules such as K-Ras, Rac1, and c-Src that are targeted to the membrane by electrostatic interactions were rapidly released from membrane subdomains where the surface charge was altered by lipid remodeling during phagocytosis.
Yeung
Tony
T
Division of Cell Biology, Hepatology, and Nutrition Department, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.
Terebiznik
Mauricio
M
Yu
Liming
L
Silvius
John
J
Abidi
Wasif M
WM
Philips
Mark
M
Levine
Tim
T
Kapus
Andras
A
Grinstein
Sergio
S
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology*; D005456:Fluorescent Dyes / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D007074:Immunoglobulin G / Q000276:immunology; D015759:Ionomycin / Q000494:pharmacology; D008051:Lipid Bilayers / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008264:Macrophages / Q000502:physiology*; D008564:Membrane Potentials; D051379:Mice; D015335:Molecular Probes / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D009895:Opsonin Proteins; D010455:Peptides / Q000378:metabolism; D010587:Phagocytosis; D010588:Phagosomes / Q000502:physiology; D010743:Phospholipids / Q000032:analysis / Q000378:metabolism; D011961:Receptors, Fc / Q000276:immunology / Q000378:metabolism; D055672:Static Electricity; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020830:rac1 GTP-Binding Protein; D018631:ras Proteins / Q000378:metabolism
D005456:Fluorescent Dyes; D007074:Immunoglobulin G; D008051:Lipid Bilayers; D008081:Liposomes; D015335:Molecular Probes; D009479:Neuropeptides; D009895:Opsonin Proteins; D010455:Peptides; D010743:Phospholipids; C484602:Rac1 protein, mouse; D011961:Receptors, Fc; D015759:Ionomycin; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D018631:ras Proteins; D002118:Calcium