Table 1.

Characteristics of F-actin-associating BAR domain proteins

Protein	Domain type	Affinity to F-actin (K d)	Interaction site	Function (in vitro)a	Function (in vivo)a
PICK1	N-BAR	0.3 µM [105]b 2.0–3.0 μM [78]c	BAR domain K251, K252 [105]	1. Inhibits Arp2/3-mediated actin nucleation [105]d 2. Binds to F-actin, but it neither binds nor inhibits Arp2/3 complex [78]	1. Contribution to specific form of vesicle trafficking, and the development of neuronal architecture [105] 2. No colocalization and binding with actin in vivo [78]
Gas7	F-BAR	0.3 µM [104]e	BAR domain [104]f	Promotes actin assembly and crosslinks actin filaments [104]	Reorganization of microfilaments and promoting of membrane outgrowth [104]
PSTPIP2	F-BAR	N.D	BAR domain [106]f, g	Induces actin bundling, reduces the rate of actin polymerization, and increases its stability [106]	Effects on actin bundling and filopodia formation, and directional migration [106]
Pacsin-2	F-BAR	2.0 μM [50]	BAR domain mainly two clusters of lysine residues [50]h	Increases the stability of F-actin [50]	N.D
MIM	I-BAR	17 µM [107]	BAR domain basic residues at the distal ends of the dimer [8] i	1. Bundling of actin filaments [99, 110, 111] 2. Weak or no bundling activity [8, 107]	1. Filopodia/microspike formation [99, 111] 2. Does not contribute to filopodia formation [8]
IRSp53	I-BAR	5 µM [6]	BAR domain basic residues at the distal ends of the dimer [6]i	Bundling of actin filaments [6, 111]	Filopodia formation [6]

N.D. not determined

^aFunction related to F-actin binding

^bKd determined for the full length protein; isolated BAR domain bound to actin more efficiently than full length PICK1

^cKd determined for the full length protein

^dThrough interactions of the BAR domain with F-actin and the ACT with Arp2/3

^eDetermined indirectly by comparison with α-catenin

^fDetailed mapping was not done

^gExperiments were done with the full length protein, which does not have any other domain than BAR

^hIndentified by cross-linking; however, some other residues might be involved as well

ⁱOther parts of the I-BAR are most likely also involved