1. a b c d * MCF7.vec MCF7 IP: HA HA IgG p110 p85 14-3-3 p85WT p85S83μR X pS P K I
S83
human
bovine
mouse
rat
S84
frog
Mode 2 consensus S
S231 L
N231 C A
N230 V
Mode 1 consensus T Q
S154
S153
IP: HA HA
IgG
p110
p85
14-3-3
p85WT
p85S83μ
p85S154/231μ
p85
HA 
IP: Xpress
MCF7 c d
Vector
p85WT
p85S83μ
HA 
p85 *
MCF7
Supplementary Figure S binds to serine 83 on p85 and activates PI3K/Akt.
a. MCF7 HA-tagged ζ (MCF7) stable transfectants and their respective vector control cells (MCF7.vec) were immunoprecipitated (IP) with anti-HA or IgG followed by immunoblot with p110, p85, and  antibodies.
b. Potential binding motifs encompassing serine 83, serine 154 and serine 231 in human p85a compared to other organisms.
c. MCF7ζ transfectants were stably transfected with empty vector (vector), histidine/Xpress-tagged (His/Xpress) wild type p85 (p85WT), or tagged p85 mutated in the binding site encompassing S83 (p85S83μ) and immunoblotted with the indicated antibodies. Asterisk indicates tagged p85.
d. MCF7 histidine/Xpress-tagged p85WT, p85S83μ or p85S154/231μ stable transfectants
were immunoprecipitated (IP) with Xpress antibody followed by immunoblot with HA to detect
exogenous ζ. Immunoprecipitation efficiency of Xpress-tagged p85 was determined by
immunoblot with p85 antibody.