TABLE III.
Arp2/3 Subunitsa
| Protein | Molecular weight (kDa) |
Protein family | Interaction with actin |
Interaction with other Arp2/3 subunits |
Activity |
|---|---|---|---|---|---|
| Arp3 | 47 | Actin-related protein |
Pointed-end binding |
ARC2 ARC3 ARC4 |
NA |
| Arp2 | 44 | Actin-related protein |
Pointed-end binding |
ARC1 ARC2 |
Antibody blocks polymerization in vitro; antibody blocks platelet shape change morphologically |
| ARC1 | 40 | 7 WD repeats | Filament side binding |
Arp2 ARC2 |
— |
| ARC2 | 34 | — | Branching, side binding |
Arp2 Arp3 ARC1 ARC4 |
Antibody blocks branching in vitro; antibody blocks propulsion but not polymerization in cells |
| ARC3 | 21 | — | Arp3 ARC4 |
Binds WASp/SCAR; mediate activation of Arp2/3 | |
| ARC4 | 20 | — | Arp3 ARC2 |
— | |
| ARC5 | 16 | — | ARC3 ARC4 |
— — |
a
References as in text and as reported in Higgs and Pollard (2001).