Mammalian actin-related protein 2/3 complex localizes to regions of lamellipodial protrusion and is composed of evolutionarily conserved proteins.
Human neutrophils contain a complex of proteins similar to the actin-related protein 2/3 (Arp2/3) complex of Acanthamoeba. We have obtained peptide sequence information for each member of the putative seven-protein complex previously described for Acanthamoeba and human platelets. From the peptide sequences we have identified cDNA species encoding three novel proteins in this complex. We find that in addition to Arp2 and Arp3, this complex contains a relative of the human (Suppressor of Profilin) SOP2Hs protein and four previously unknown proteins. These proteins localize in the cytoplasm of fibroblasts that lack lamellipodia, but are enriched in lamellipodia on stimulation with serum or platelet-derived growth factor. We propose a conserved and dynamic role for this complex in the organization of the actin cytoskeleton.
Machesky
L M
LM
Department of Medicine, University College London, U.K.
Reeves
E
E
Wientjes
F
F
Mattheyse
F J
FJ
Grogan
A
A
Totty
N F
NF
Burlingame
A L
AL
Hsuan
J J
JJ
Segal
A W
AW
D016475:3T3 Cells; D000048:Acanthamoeba / Q000737:chemistry; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D017124:Conserved Sequence; D003598:Cytoskeletal Proteins; D019143:Evolution, Molecular; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000737:chemistry; D015800:Protozoan Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics
C495926:ACTR2 protein, human; C495928:ACTR3 protein, human; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; C495927:Actr2 protein, mouse; C495929:Actr3 protein, mouse; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D046911:Macromolecular Substances; D015800:Protozoan Proteins