SWAP-70 associates transiently with macropinosomes.
Cells accomplish the non-selective uptake of extracellular fluids, antigens and pathogens by the endocytic process of macropinocytosis. The protein SWAP-70 is a widely expressed, pleckstrin-homology (PH) domain-containing protein that marks a transitional subset of actin filaments in motile cells. Here we report that the protein SWAP-70 associates transiently with macropinosomes in dendritic cells and NIH/3T3 fibroblasts. The association of SWAP-70 with macropinosomes is preceded by the accumulation of Rac-GTP and followed by that of Rab5. Three regions of SWAP-70, the N-terminal region, the PH domain and the C-terminal region, contribute in a combinatorial manner to the transient association with newly formed macropinosomes in the cell periphery and occasionally with aged macropinosomes on their passage to the cell center. These data identify SWAP-70 as a transient component of early macropinosomes.
Oberbanscheidt
Pia
P
Institut für Allgemeine Zoologie und Genetik, Westfälische Wilhelms-Universität Münster, Schlossplatz 5, D-48149 Münster, Germany.
Balkow
Sandra
S
Kühnl
Jochen
J
Grabbe
Stephan
S
Bähler
Martin
M
D000818:Animals; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D015778:Minor Histocompatibility Antigens; D009687:Nuclear Proteins / Q000378:metabolism*; D010873:Pinocytosis / Q000502:physiology*; D022161:Transport Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism
D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D015778:Minor Histocompatibility Antigens; D009687:Nuclear Proteins; C113365:Swap70 protein, mouse; D020696:rab5 GTP-Binding Proteins; D020744:rac GTP-Binding Proteins