Table 1.

S474 PAK4 kinase phosphorylation: characteristics and interactions of PAK4 in rat pancreatic acini

Variable	pS474 PAK4 Phosphorylation	Concentrations and Incubation Times Reported In:
Stimulation by pancreatic secretagogues		Fig. 2
Yes	Endothelin-1, CCK-8, carbachol, bombesin
Stimulation by pancreatic growth factors		Fig. 2
Yes	Insulin, IGF-1, HGF, EGF, bFGF, PDGF
Stimulation by post-receptor activators		Fig. 5
Yes	TPA, thapsigargin, A23187
Potency/Time course		Fig. 3
EC50 of CCK-8 (nM)	0.052 ± 0.003	Fig. 3
EC50 of CCK-JMV (nM)	0.10 ± 0.01	Fig. 3
Inhibition of CCK-8-stimulated PAK4 activation
Inhibition of 0.3 nM CCK-8		Fig. 7
Yes	p38 Inhibitor (SB202190), SFK inhibitor (PP2)
No	p44/42 inhibitor (PD98059)
Inhibition of 1 nM CCK-8		Figs. 5–7
Yes	PKD inhibitor (CRT0066101, kbNB142–70), PKC (GFX109203)
No	PI3K inhibitor (wortmannin, LY294002), Ca2+ (Thapsigargin)
Inhibition of 100 nM CCK-8		Fig. 7
Yes	p44/42 Inhibitor (PD98059)
No	p38 Inhibitor (SB202190), SFK Inhibitor (PP2)
Inhibition by PF-3758309		Fig. 8
PAK4	From 0.1 nM (IC50: 1.89 ± 0.02 nM)
PAK2	Requires high doses (i.e., ≥1 µM of PF-37580309)
Inhibition by LCH-7749944		Fig. 9
PAK4	90% decrease at 3 s incubation with 30 µM LCH-7749944
PAK2	No inhibition under these conditions

Results are calculated from data shown in Figs. 2, 3, 5–9. bFGF, basic fibroblast growth factor; CCK, cholecystokinin; EGF, epidermal growth factor; HGF, hepatocyte growth factor; IGF-1, insulin-like growth factor 1; PAK, p21-activated kinase; PDGF, platelet-derived growth factor; SFK, Src family of kinases.