REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Anti-ERα, rabbit (for CLIP)	Santa Cruz	Cat# sc-542; RRID:AB_631470
Anti-ERα, rabbit (for IP & mass spec)	Cell Signaling Technology	Cat# 8644S; RRID:AB_2617128
Anti-FLAG (M2), mouse	Sigma	Cat# F1804; RRID:AB_262044
Anti-IgG, rabbit	Cell Signaling Technology	Cat# 2729S; RRID:AB_1031062
Anti-Lamin A/C, mouse	Santa Cruz	Cat# sc-7292; RRID:AB_627875
Anti-α-tubulin, mouse	Abcam	Cat# ab18251; RRID:AB_2210057
Anti-SMC2, rabbit	Cell Signaling Technology	Cat# 5329S; RRID:AB_10693789
Anti-PABP1, rabbit	Cell Signaling Technology	Cat# 4992S; RRID:AB_10693595
Anti-eIF4A1, mouse (for IP and western)	MyBioSource	Cat# MBS8504039
Anti-eIF4G2, mouse (for western and IHC)	Proteintech	Cat# 67428-1-Ig; RRID:AB_2882667
Anti-RtcB, rabbit	Proteintech	Cat# 19809-1-AP; RRID:AB_10695047
Anti-MCL1, rabbit (for western and IHC)	Santa Cruz	Cat# sc-819; RRID:AB_2144105
Anti-β-actin, mouse	Sigma	Cat# A5316; RRID:AB_476743
Anti-Histone H3,	Cell Signaling Technology	Cat# 14269S; RRID:AB_2756816
Anti-XBP1s, rabbit (for western and IHC)	Cell Signaling Technology	Cat# 12782S; RRID:AB_2687943
Bacterial and virus strains
MAX Efficiency DH5α Competent Cells	Life Technologies	Cat# 18258012
One Shot, BL21(DE3), E. coli	Life Technologies	Cat# C601003
Biological samples
Human breast cancer TMAs	US Biomax	https://www.biomax.us/tissue-arrays/Breast/BC081116d
Chemicals, peptides, and recombinant proteins
Oligo(dT)-cellulose beads	Sigma	Cat# O3131
TRIzol	Life Technologies	Cat# 15596026
Glycoblue	Life Technologies	Cat# AM9515
IPTG	Thermo Fisher Scientific	Cat# 15529-019
BSA	Sigma	Cat# A7030
TURBO DNA-free Kit	Thermo Fisher Scientific	Cat# AM1907
cOmplete, Mini, EDTA-free Protease Inhibitor Cocktail tablet	Roche	Cat# 11836170001
Protein A Dynabeads	Thermo Fisher Scientific	Cat# 10008D
DNase RQ1 (1unit/ul)	Promega	Cat# M6101
RNasin plus (40unit/uL)	Promega	Cat# N2615
RNase A	Affymetrix	Cat# 70194Z
Calf alkaline phosphatase (10 unit/ul)	NEB	Cat# M0290
T4 Polynucleotide kinase (10 unit/ul)	NEB	Cat# M0201
T4 RNA ligase (10 unit/ul)	Thermo Fisher Scientific	Cat# EL0021
Chloroform:isoamyl alcohol 49:1	Sigma	Cat# 25668
Acid phenol	Sigma	Cat# P4682
Proteinase K (lyophilized)	Roche	Cat# 03115879001
3M NaOAc pH 5.5	Thermo Fisher Scientific	Cat# AM9740
Superscript III reverse transcriptase	Thermo Fisher Scientific	Cat# 18080093
Accuprime pfx supermix	Thermo Fisher Scientific	Cat# 12344-040
IGEPAL CA-630	Sigma	Cat# I8896
PhosSTOP™	Sigma	Cat# 4906837001
Critical commercial assays
RNeasy Mini Kit	Qiagen	Cat# 74106
QIAprep Spin Miniprep Kit (250)	Qiagen	Cat# 27106
RNA Clean & Concentrator™ Kits	Zymo Research	Cat# R1016
ATP, [γ-32P]-6000Ci/mmol 10mCi/ml EasyTide	Perkinelmer	Cat# BLU502Z250UC
QIAquick Gel Extraction Kit	Qiagen	Cat# 28706
MinElute Reaction Cleanup Kit	Qiagen	Cat# 28204
QuantiFluor dsDNA Sample Kit	Promega	Cat# E2671
High Sensitivity DNA Kit	Agilent	Cat# 5067-4626
NEBNext Ultra II DNA Library Prep with Sample Purification Beads	NEB	Cat# E7103S
NEBNext Multiplex Oligos for Illumina (Index Primers Set 1)–24 rxns	NEB	Cat# E7335S
Deposited data
Sequencing data	This Study	GEO: GSE173631
Mass spectrometry data	This Study	ProteomeXchange: PXD025018
Experimental models: Cell lines
MCF7	ATCC	Cat# HTB-22; RRID:CVCL_0031
T47D	ATCC	Cat# HTB-133; RRID:CVCL_0553
TamR-1	Sigma	Cat# SCC101; RRID:CVCL_M436
TamRM	(Raha et al., 2015)	N/A
HEK293T	ATCC	Cat# CRL-3216; RRID:CVCL_0063
Software and algorithms
Bowtie2	(Langmead and Salzberg, 2012)	http://bowtie-bio.sourceforge.net/bowtie2/ Salzberg, 2012) index.shtml
Prism 8	GraphPad	https://graphpad.com
ImageJ	NIH	https://imagej.nih.gov/ij
CPTAC-BRCA2020 data viewer	(Krug et al., 2020)	http://prot-shiny-vm.broadinstitute.org:3838/CPTAC-BRCA2020
Cistrome	(Liu et al., 2011)	http://cistrome.org/ap/
phastCons	(Siepel et al., 2005)	http://compgen.cshl.edu/phast/phastCons-HOWTO.html
RStudio	RStudio	Rstudio.com
IGV	(Robinson et al., 2011)	http://software.broadinstitute.org/software/igv/download
MACS2	(Zhang et al., 2008)	https://github.com/taoliu/MACS
ChAsE	(Younesy et al., 2016)	https://chase.cs.univie.ac.at
Flow Jo	Flow Jo	https://www.flowjo.com/
Cutadapt v.1		https://cutadapt.readthedocs.io/en/stable/
BWA v.0.7	(Li and Durbin, 2009)	https://sourceforge.net/projects/bio-bwa/
The CLIP tool kit (CTK)	(Shah et al., 2017)	https://zhanglab.c2b2.columbia.edu/index.php/CTK_Documentation
Kmplot	(Gyorffy et al., 2010)	https://kmplot.com/analysis/index.php?p=service&cancer=breast