KEY RESOURCES TABLE

REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Flag 1:1,000	Sigma	V8137
SPRED1 1:1,000	Cell Signaling	94063
α/β-Tubulin 1:2,000	Cell Signaling	2148
EGFR 1:200	Santa Cruz Biotech	1005, SC-03
Neurofibromin 1:200	Santa Cruz Biotech	SC-67
RAS 1:200	Cytoskeleton	AESA02
β-Actin 1:10,000	Sigma-Aldrich	A5441
Bacterial and Virus Strains
BL21 STAR (DE3)	Thermo Fisher	C601003
Tni-FNL insect cells	FNLCR	Tni-FNL
Baculovirus, Bac-to-Bac	Thermo Fisher	AcMNPV
Retrovirus: pMD2.G	Addgene	12259
Retrovirus: gag/pol	Addgene	14887
Biological Samples
HEK293T	UCSF Cell and Genome Engineering Core	CCLZR076
K562	UCSF Cell and Genome Engineering Core	CCLZR466
Chemicals, Peptides, and Recombinant Proteins
protease inhibitor (PI) cocktail	Sigma-Aldrich	P8849, P8340
ANAPOE®-80	Molecular Dimensions	APT080 500 ML
PGA-LM	Molecular Dimensions	MD2-250-108
PEG3350 (50% w/v)	Hampton Research	HR2-527
DMEM, high glucose	Thermo Fisher	11965-084
RPMI 1640	Thermo Fisher	118775-093
FBS	Atlanta Biologicals	S11550H
Penicillin-Streptomycin	Thermo Fisher	15140-122
Opti-MEM Reduced Serum Medium	Thermo Fisher	51985091
phosphatase inhibitors	Sigma Aldrich	P0044, P5726
EGF	Thermo Fisher	PHG0311
Nuclear and Cytoplasmic Extraction Reagents	Thermo Fisher	78835
Lipofectamine 3000 Transfection Reagent	Thermo Fisher	L3000015
ViralBoost Reagent	Alstem	VB1000
trypsin	Sigma Trypsin Singles	T7575
Critical Commercial Assays
RAS Pull-down Activation Assay Biochem Kit	Cytoskeleton	BK008
Lipofectamine 2000 Transfection Reagent	Thermo Fisher	11668019
Deposited Data
Crystal structure of KRAS-NF1-SPRED1	This study	PDB:6V65
Crystal structure of KRAS(Q61L)-NF1-SPRED1	This study	PDB:6V6F
Experimental Models: Cell Lines
HEK293T	UCSF Cell and Genome Engineering Core	CCLZR076
K562	UCSF Cell and Genome Engineering Core	CCLZR466
Spred1(S105A)-Forward PrimerGGTCTTACGTTTCAAGCTCCTGCTGATGCTAGG	Sigma-Aldrich	N/A
Spred1(S105A)-Reverse PrimerCCTAGCATCAGCAGGAGCTTGAAACGTAAGACC	Sigma-Aldrich	N/A
Spred1(S105D)-Forward PrimerGTTTGGTCTTACGTTTCAACATCCTGCTGATGCTAGGGC	Sigma-Aldrich	N/A
Spred1(S105D)-Reverse PrimerGCCCTAGCATCAGCAGGATGTTGAAACGTAAGACCAAAC	Sigma-Aldrich	N/A
Spred1(S105E)-Forward PrimerGGTCTTACGTTTCAAGAACCTGCTGATGCTAG	Sigma-Aldrich	N/A
Spred1(S105E)-Reverse PrimerCTAGCATCAGCAGGTTCTTGAAACGTAAGACC	Sigma-Aldrich	N/A
Spred1(W31C)-Forward PrimerCTCAAGTGGTGGATGCTTACCACTTGGAGGG	Sigma-Aldrich	N/A
Spred1(W31C)-Reverse PrimerCCCTCCAAGTGGTAAGCATCCACCACTTGAG	Sigma-Aldrich	N/A
Spred1(T102R)-Forward PrimerCAAGAAGTTTGGTCTTAGGTTTCAAAGTCCTGCTG	Sigma-Aldrich	N/A
Spred1(T102R)-Reverse PrimerCAGCAGGACTTTGAAACCTAAGACCAAACTTCTTG	Sigma-Aldrich	N/A
Recombinant DNA
pDZ2087 (Expresses TEV protease in E. coli)	Addgene	92414
pMIG	Addgene	9044
pMD2.G	Addgene	12259
SPRED1 expression plasmid for cellular assay	(Stowe et al., 2012)	N/A
Software and Algorithms
XDS	(Kabsch, 2010)	N/A
Phaser	(McCoy et al., 2007)	N/A
Phenix	(Adams et al., 2010)	N/A
COOT	(Emsley et al., 2010)	N/A
DSSP	https://swift.cmbi.umcn.nl/gv/dssp/).	N/A
PyMOL	Schrödinger, LLC	Ver: 2.3.2
SBGrid Consortium	(Morin et al., 2013)	N/A
PDBSum	http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/pdbsum/GetPage.pl?pdbcode=index.html/	N/A
MicroCal PEAQ-ITC analysis software	Malvern	N/A
Proteome Discoverer	Thermo Fisher	Ver: 1.4
Protein Prospector	(Baker and Chalkley, 2014; Chalkley et al., 2005)	Ver: 5.14.0
SwissProt database	(Bairoch and Apweiler, 2000)	N/A
Skyline v 3.0	(MacLean et al., 2010)	V 3.0
Other
Immobilized metal affinity chromatography columns	GE Healthcare	18-1174-40
NGC chromatography system	Bio-Rad Laboratories	NGC-100
10K MWCO Amicon centrifugation units	MilliporeSigma	UFC901008
MicroCal PEAQ-ITC	Malvern	N/A
Anti-FLAG antibodies coupled to magnetic beads	Sigma	M8823
Liquid chromatography tandem mass spectrometry	Thermo Fisher	N/A
Silica-C18 EasySpray column	Thermo Fisher	N/A