Supporting Information
Supporting Table 1. Nonredundant peptides identified using tyrosine phosphopeptide enrichment and
PolyMAC. Lower case y, s, or t indicate assigned sites of phosphorylation.
[Attached separately as Supporting_Table_1.tsv]
Supporting Table 2. Nonredundant peptides identified using PolyMAC on RPLC pH 8 fractions. Lower
case y, s, or t indicate assigned sites of phosphorylation.
[Attached separately as Supporting_Table_2.tsv]
Supporting Figure 1. Linear motifs identified by motif-x for phosphotyrosines, phosphoserines, and
phosphothreonines. The phosphosite is located at position 0. Note that motif-x identifies motifs
sequentially, excluding matches from the subsequent iterations until no more significant motifs are
identified. Thus, the underlying true linear motifs may be identified more than once due to random
variation.
Supporting Table 3. Selected evidence for identified therapeutic targets.
Gene Symbol
Phosphosites
Detected
Known
Suspected Role Inhibitors
Activating Site in Breast
Cancer
Clinical Status
Epha2
Y589, Y595,
Y773
Yes [1]
Metastasis [2]
Dasatinib
FDA-approved
Fyn
Y213
Yes [3]
Invasion,
metastasis [4]
Dasatinib
FDA-approved
Lyn
Y397
Yes [5]
Invasion,
metastasis [6]
Dasatinib,
Bafetinib
FDA-approved
Btk
Y551
Yes [7]
Survival [8]
Ibrutinib
FDA-approved
Stat3
Y705
Yes [9]
Proliferation,
ISIS-STAT3
survival
invasion,
metastasis [10]
Phase 1/2
Ptk2
(Fak)
Y397, Y407
Yes [11]
Proliferation,
invasion,
metastasis,
angiogenesis
[12]
Phase 3
Ptk2b
(Pyk2)
Y579
Yes [11]
Proliferation,
Leflunomide,
invasion,
Genistein
metastasis [13]
FDA-approved,
Phase 2/3
Ptpre
(RPTP)
Y695
Yes [14]
Proliferation,
invasion,
FDA-approved
Masitinib
Alendronate
metastasis [14]
Mapk1
(Erk2)
Y185
Yes [15]
Proliferation,
Sorafenib
survival,
invasion,
metastasis [16]
FDA-approved
Mapk3
(Erk1)
Y205
Yes [15]
Often not
distinguished
from Mapk1
FDA-approved
Sorafenib
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