Barbano et al. 10.1073/pnas.0709955104.
SI Text
The Full Network with 102 Components
The DARPP-32 network depicted in Fig. 1 highlights 45 key species. The full network includes a number of enzyme-substrate complexes such as PKA-cAMP bound to DARPP-32-T75P. These species account for the increase in the number of chemical species present from 45 to 102. For clarity, these additional species are indicated with the annotation "complex" in the list below. (Free phosphate is assumed to be in abundance and not considered as a separate variable.)
The list of components below contains a few molecules that were not included in Fig. 1 as parts of the network. They were introduced because the four enzymes regulating the Ser-97 and Ser-130 phosphorylation states of DARPP-32, namely, CK1-P, PP-1, CK2, and PP2C, were treated inconsistently in the available model. More precisely, while CK1-P is regulated by the transient impulse of glutamate, the other three enzymes were uncoupled from either of the neurotransmitters being studied. We, therefore, chose to create several artificial activators: Dummy-Activator-PP1, Dummy-Activator-CK2, and Dummy-Activator-PP2C. In the absence of these dummy activators, DARPP-32 was overwhelmingly driven to the Ser102P phosphorylation state, leaving meaningful variation only between the Thr-34 and Thr-75 phosphorylation sites, instead of all four sites present in the model. The three dummy activators correct this imbalance. In essence, the three "unregulated" enzymes are provided with artificial activation impulses that mimic the specified impulses of dopamine and glutamate.
Component list:
1 DARPP-32-T75P
2 DARPP-32
3 DARPP-32-T34P
4 PP2A-P
5 PP2A
6 PKA-cAMP
7 PKA-cAMP-DARPP-32-T75P (complex)
8 Cdk5-P
9 PP2B-Ca2+
10 DARPP-32-T75P-PP2A-P (complex)
11 DARPP-32-Cdk5-P (complex)
12 DARPP-32-PKA-cAMP (complex)
13 DARPP-32-T34P-PP2B-Ca2+ (complex)
14 PP2A-PKA-cAMP (complex)
15 PKA
16 cAMP
17 ATP
18 Ga
19 D1R
20 Dopamine
21 Cdk5
22 CK1-P
23 CK1
24 PP2B
25 Ca2+
26 IP3
27 PIP2
28 PLC-Gq
29 PLC
30 Gq
31 mGluR
32 Glutamate
33 Cdk5-CK1-P (complex)
34 PP2B-Ca2+ -CK1 (complex)
35 PLC-Gq-PIP2 (complex)
36 PP-1
37 PP-1-DARPP-32-T34P (complex)
38 Adenylyl Cyclase
39 Adenylyl Cyclase-Ga
40 Adenylyl Cyclase-Ga-ATP (complex)
41 DARPP-32-S97P
42 CK2-P
43 CK2-P-DARPP-32 (complex)
44 PP-1-DARPP-32-S97P
45 DARPP-32-T75P-S97P
46 Cdk5-P-DARPP-32-S97P (complex)
47 PP2A-DARPP-32-T75P-S97P (complex)
48 CK2-P-DARPP-32-T75P (complex)
49 PP-1-DARPP-32-T75P-S97P (complex)
50 PKA-cAMP-DARPP-32-T75P-S97P (complex)
51 DARPP-32-T34P-S97P
52 PKA-cAMP-DARPP-32-S97P (complex)
53 PP2B-Ca2+ -DARPP-32-T34P-S97P (complex)
54 CK2-P-DARPP-32-T34P (complex)
55 PP-1-DARPP-32-T34P-S97P (complex)
56 PP-1-DARPP-32-T34P-S97P
57 DARPP-32-S130P
58 PP2C
59 CK1-P-DARPP-32 (complex)
60 PP2C-DARPP-32-S130P (complex)
61 DARPP-32-T75P-S130P
62 Cdk5-P-DARPP-32-S130P (complex)
63 PP2A-P-DARPP-32-T75P-S130P (complex)
64 CK1-P-DARPP-32-T75P (complex)
65 PP2C-DARPP-32-T75P-S130P (complex)
66 PKA-cAMP-DARPP-32-T75P-S130P
67 DARPP-32-T34P-S130P
68 PKA-cAMP-DARPP-32-S130P (complex)
69 PP2B-Ca2+ -DARPP-32-T34P-S130P (complex)
70 CK1-P-DARPP-32-T34P (complex)
71 PP2C-DARPP-32-T34P-S130P (complex)
72 PP-1-DARPP-32-T34P-S130P
73 DARPP-32-T75P-S97P-S130P
74 CK1-P-DARPP-32-T75P-S97P (complex)
75 PP2C-DARPP-32-T75P-S97P-S130P (complex)
76 CK2-P-DARPP-32-T75P-S130P (complex)
77 PP-1-DARPP-32-T75P-S97P-S130P (complex)
78 PKA-cAMP-DARPP-32-T75P-S97P-S130P
79 DARPP-32-T34P-S97P-S130P
80 CK1-P-DARPP-32-T34P-S97P (complex)
81 PP2C-DARPP-32-T34P-S97P-S130P (complex)
82 CK2-P-DARPP-32-T34P-S130P (complex)
83 PP-1-DARPP-32-T34P-S97P-S130P (complex)
84 PP-1-DARPP-32-T34P-S97P-S130P
85 DARPP-32-S97P-S130P
86 CK1-P-DARPP-32-S97P (complex)
87 PP2C-DARPP-32-S97P-S130P (complex)
88 CK2-P-DARPP-32-S130P (complex)
89 PP-1-DARPP-32-S97P-S130P (complex)
90 PP2A-P-DARPP-32-T75P-S97P-S130P (complex)
91 Cdk5-P-DARPP-32-S97P-S130P (complex)
92 PP2B-Ca2+ -DARPP-32-T34P-S97P-S130 (complex)
93 PKA-cAMP-DARPP-32-S97P-S130P (complex)
94 PP1-inactive
95 Dummy-Activator-PP1
96 PP1-Dummy (complex)
97 CK2-inactive
98 Dummy-Activator-CK2
99 CK2-Dummy (complex)
100 PP2C-inactive
101 Dummy-Activator-PP2C
102 PP2C-Dummy (complex)
MATLAB or C codes for setting up the random parameters and solving the system of ordinary differential equations are available by request from the authors (greengard@courant.nyu.edu or spivak.marina@gmail.com).