Profilin is a conserved, widely distributed actin monomer binding protein found in eukaryotic cells. Mammalian profilin reversibly sequesters actin monomers in a high affinity profilactin complex. In vitro, the complex is dissociated in response to treatment with the polyphosphoinositides, phosphatidylinositol monophosphate, and phosphatidylinositol 4,5-bisphosphate. Here, we demonstrate the ultrastructural immunolocalization of profilin in human leukocytes and platelets. In both cell types, a significant fraction of profilin is found associated with regions of cell membrane devoid of actin filaments and other discernible structures. After platelet activation, the membrane association of profilin reversibly increases. This study represents the first direct evidence for an interaction between profilin and phospholipids in vivo.
Article|
October 01 1989
Association of profilin with filament-free regions of human leukocyte and platelet membranes and reversible membrane binding during platelet activation.
J H Hartwig,
J H Hartwig
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
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K A Chambers,
K A Chambers
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
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K L Hopcia,
K L Hopcia
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
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D J Kwiatkowski
D J Kwiatkowski
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
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J H Hartwig
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
K A Chambers
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
K L Hopcia
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
D J Kwiatkowski
Department of Medicine, Massachusetts General Hospital, Charlestown 02129.
Online Issn: 1540-8140
Print Issn: 0021-9525
J Cell Biol (1989) 109 (4): 1571–1579.
Citation
J H Hartwig, K A Chambers, K L Hopcia, D J Kwiatkowski; Association of profilin with filament-free regions of human leukocyte and platelet membranes and reversible membrane binding during platelet activation.. J Cell Biol 1 October 1989; 109 (4): 1571–1579. doi: https://doi.org/10.1083/jcb.109.4.1571
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