Adapter protein implicated in the regulation of a large spectrum of both general and specialized signaling pathways (PubMed:21189250). Binds to a large number of partners, usually by recognition of a phosphoserine or phosphothreonine motif (PubMed:35343654). Binding generally results in the modulation of the activity of the binding partner (By similarity). Positively regulates phosphorylated protein HSF1 nuclear export to the cytoplasm (PubMed:12917326). Plays a positive role in the antiviral signaling pathway upstream of TBK1 via interaction with RIGI (PubMed:37555661). Mechanistically, directs RIGI redistribution from the cytosol to mitochondrial associated membranes where it mediates MAVS-dependent innate immune signaling during viral infection (PubMed:22607805). Plays a role in proliferation inhibition and cell cycle arrest by exporting HNRNPC from the nucleus to the cytoplasm to be degraded by ubiquitination (PubMed:37599448). {ECO:0000250|UniProtKB:P62261, ECO:0000269|PubMed:12917326, ECO:0000269|PubMed:21189250, ECO:0000269|PubMed:22607805, ECO:0000269|PubMed:35343654, ECO:0000269|PubMed:37555661, ECO:0000269|PubMed:37599448}. This is the function of ENSG00000108953 (YWHAE, tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein epsilon).