REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Mouse anti-β-Actin (8226)	Abcam	Cat# ab8226; RRID AB_306371
Rabbit anti-Biotin (D5A7)	Cell Signaling Technology	Cat# 5597S; RRID AB 10828011
Streptavidin-Alexa Fluor 647	Invitrogen	Cat# S21374; RRID AB_2336066
Rabbit anti-Arc	P. Worley (Hopkins)	Lyford et al., 1995
Rabbit anti-Fos (9F6)	Cell Signaling Technology	Cat# 2250S; RRID AB_2247211
Rabbit anti-NPAS4	Y. Lin (MIT)	Lin et al., 2008
Mouse anti-PSD-95 (7E31B8)	Pierce	Cat# MA1046; RRID AB_2092361
Mouse anti-UBE3A (330)	Sigma-Aldrich	Cat# E8655; RRID AB_261956
Mouse anti-Ubiquitin (FK2)	Enzo Life Sciences	Cat# PW8810; RRID AB_2051891
Mouse anti-S6 ribosomal subunit (54D2)	Cell Signaling Technology	Cat# 2317S; RRID AB_2238583
Mouse anti-Transferrin receptor (H68.4)	Invitrogen	Cat# 136800; RRID AB_2533029
Mouse anti-β2 proteasome subunit (MCP168)	Enzo Life Sciences	Cat# PW8145; RRID AB_2052386
Mouse anti-α1–7 proteasome subunit (MCP231)	Enzo Life Sciences	Cat# PW8195; RRID AB_2052368
Goat anti-Rabbit IgG, (H+L), HRP	Cell Signaling Technology	Cat# 7074S; RRID AB_2099233
Horse anti-Mouse IgG, (H+L), HRP	Cell Signaling Technology	Cat# 7076S; RRID AB_330924
Chemicals, Peptides, and Recombinant Proteins
Poly-L-Lysine (PLL)	Sigma-Aldrich	Cat# P4707
Papain	Worthington	Cat# LS003127
B27	Thermo Fisher Scientific	Cat# 17504044
Neurobasal	Thermo Fisher Scientific	Cat# 21103049
Neurobasal minus met/cys	Thermo Fisher Scientific	Cat# 21103049* special order
Penicillin/streptomycin	Sigma-Aldrich	Cat# 15140122
L-Glutamine	Thermo Fisher Scientific	Cat# 25030081
Trypsin	Thermo Fisher Scientific	Cat# 25200056
Trypsin Inhibitor	Sigma-Aldrich	Cat# T9253; CAS: 9035-81-8
DMEM	Thermo Fisher Scientific	Cat# 11960069
SuperAse	Thermo Fisher Scientific	Cat# AM2694
Fetal bovine serum (FBS)	Thermo Fisher Scientific	Cat# 16000044
PBS	Thermo Fisher Scientific	Cat# 10010049
cOmplete Protease inhibitor	Sigma-Aldrich	Cat# 11836170001
Proteasome substrate	Enzo Life Sciences	Cat# P802
MLN-7243	Chemie Tek	Cat# CT-M7243; CAS:1450833-55-2
Epoxomicin	UBPBio	Cat# F1400; CAS: 134381-21-8
MG-132	Cell Signaling Technology	Cat# 2194S
Precision Plus Standards	Bio-Rad	Cat# 1610374
Bicuculline	Tocris Bioscience	Cat# 013110; CAS: 53552-05-9
Cycloheximide	Sigma-Aldrich	Cat# C1988; CAS: 66-81-9
Puromycin	Sigma-Aldrich	Cat# P7255; CAS: 58-58-2
Actinomycin D	Sigma-Aldrich	Cat# A1410; CAS: 50-76-0
TTX	Tocris Bioscience	Cat# 1078; CAS: 4368-28-9
CNQX	Tocris Bioscience	Cat# 0190; CAS: 115066-14-3
APV	Tocris Bioscience	Cat# 010610; CAS: 79055-68-8
Trypsin (MS/MS)	Promega	Cat# V5111
Endoproteinase LysC (MS/MS)	Wako Chemical	Cat# 125-05061
TMT reagent (MS/MS)	ThermoFisher Scientific	Cat# 90110
National Diagnostics PROTOGEL (30%)	ThermoFisher Scientific	Cat# 50-899-90118
Ecoscint A	National Diagnostics	Cat # LS-273
Critical Commercial Assays
Proteasome purification kit	VWR International	76002-400
EasyTag EXPRESS 35S Protein Labeling Kit	Perkin-Elmer	NEG772014MC
Deposited Data
Proteomic datasets: TMT experiment	This paper	ProteomeXchange: PXD009920
Mouse RefSeq protein database (version 84)	This paper	https://www.ncbi.nlm.nih.gov/refseq/
Experimental Models: Cell Lines
HEK293	ATCC	CRL-1573
Experimental Models: Organisms/Strains
C57BL/6	Charles River	RRID: IMSR_CRL:27
Software and Algorithms
Proteome Discoverer 2.1	ThermoFisher Scientific	Cat# OPTON-30795
SEQUEST	Yates’ Lab, Eng et al., 1994	http://proteomicswiki.com/wiki/index.php/SEQUEST
Empirical Bayes method for protein differential abundance testing	Kammers et al., 2015	http://www.biostat.jhsph.edu/~kkammers/software/eupa/R_guide.html