PLX085041

GSE103531: SILAC identifies LAD1 as an oncogenic filamin binder regulating actin dynamics in response to EGF and marking aggressive breast tumors

• Organsim human
• Type RNASEQ
• Target gene
• Project ARCHS4

Mutations mimicking growth factor-induced proliferation and motility characterize some aggressive subtypes of mammary tumors. To unravel novel players, we applied phosphoproteomics on untransformed mammary cells, which were pre-stimulated with the epidermal growth factor (EGF). This analysis identified ladinin-1 (LAD1), a hitherto poorly characterized protein, as a phosphor-effector of the EGF-to-ERK pathway. We report that LAD1 is essential for mammary cell proliferation and migration. LAD1 is transcriptionally induced, undergoes phosphorylation by EGF and co-localizes with actin stress fibers. Yeast 2-hybrids and co-immunoprecipitation screens revealed that LAD1 binds with filamins, actin cross-linking proteins. Co-sedimentation analyses attribute to LAD1 a role in actin treadmilling, probably in conjuction with SFN/14-3-3sigma. Depletion of LAD1 led to a decrease in viability related transcripts, and inhibited growth of mammary xenografts in an animal model. Furthermore, LAD1 is highly expressed in two aggressive subtypes of breast cancer, as well as predicts poor patient prognosis. These studies identify a new cytoskeletal component essential for signal transduction and for the acquisition of oncogenic attributes by human mammary tumors. SOURCE: Yehoshua Enuka (ys.enuka@gmail.com) - Yarden Weizmann Institute of Science