Flotillin microdomains interact with the cortical cytoskeleton to control uropod formation and neutrophil recruitment.
We studied the function of plasma membrane microdomains defined by the proteins flotillin 1 and flotillin 2 in uropod formation and neutrophil chemotaxis. Flotillins become concentrated in the uropod of neutrophils after exposure to chemoattractants such as N-formyl-Met-Leu-Phe (fMLP). Here, we show that mice lacking flotillin 1 do not have flotillin microdomains, and that recruitment of neutrophils toward fMLP in vivo is reduced in these mice. Ex vivo, migration of neutrophils through a resistive matrix is reduced in the absence of flotillin microdomains, but the machinery required for sensing chemoattractant functions normally. Flotillin microdomains specifically associate with myosin IIa, and spectrins. Both uropod formation and myosin IIa activity are compromised in flotillin 1 knockout neutrophils. We conclude that the association between flotillin microdomains and cortical cytoskeleton has important functions during neutrophil migration, in uropod formation, and in the regulation of myosin IIa.
MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, England, UK.
Alexander
A
Ludwig
Grant P
GP
Otto
Kirsi
K
Riento
Emily
E
Hams
Padraic G
PG
Fallon
Ben J
BJ
Nichols
D000818:Animals; D022081:Cell Surface Extensions / Q000378:metabolism*; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology*; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013049:Spectrin / Q000378:metabolism
D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; C106354:flotillins; D013049:Spectrin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D024507:Nonmuscle Myosin Type IIA