biostudies-literatureHanson RLNCI NIH HHS39996-40011https://www.ebi.ac.uk/biostudies/studies/S-EPMC5129987biostudies-literatureUnknown7(26)The MUC1 glycoprotein is overexpressed and aberrantly glycosylated in >90% of pancreatic ductal adenocarcinoma cases and impacts tumor progression by initiating downstream signaling through phosphorylation of its cytoplasmic tail. Previous studies have demonstrated that MUC1 alters expression of known targets of activator protein 1 (AP-1); however, no studies have evaluated the precise impact of MUC1 signaling on the activity and formation of AP-1. Given the known role of these proteins in modulating migration, invasion, and tumor progression, we explored the effects of MUC1 on AP-1 dimer formation and function. We determined that MUC1 increased the protein levels of c-Jun, the major component of AP-1, and promoted dimerization of c-Jun with the Fos-protein FRA-1. We demonstrate that FRA-1OncotargetIdentification of FRA-1 as a novel player in pancreatic cancer in cooperation with a MUC1: ERK signaling axis.PMC5129987U01 CA111294P30 CA036727U54 CA163120P50 CA127297R01 CA057362T32 CA009476Steele MMGrunkemeyer JAGrandgenett PMHanson RLBrown RBHollingsworth MAfalseIdentification of FRA-1 as a novel player in pancreatic cancer in cooperation with a MUC1: ERK signaling axis.The MUC1 glycoprotein is overexpressed and aberrantly glycosylated in >90% of pancreatic ductal adenocarcinoma cases and impacts tumor progression by initiating downstream signaling through phosphorylation of its cytoplasmic tail. Previous studies have demonstrated that MUC1 alters expression of known targets of activator protein 1 (AP-1); however, no studies have evaluated the precise impact of MUC1 signaling on the activity and formation of AP-1. Given the known role of these proteins in modulating migration, invasion, and tumor progression, we explored the effects of MUC1 on AP-1 dimer formation and function. We determined that MUC1 increased the protein levels of c-Jun, the major component of AP-1, and promoted dimerization of c-Jun with the Fos-protein FRA-1. We demonstrate that FRA-12016-01-01T00:00:00Z2016 Jun2026-05-02T10:40:31.906Z2025-05-29T19:21:51.963ZS-EPMC51299872722088910.18632/oncotarget.9557