The phrase "initiation factor" refers to a molecule or a group of molecules that helps start a specific process. It is like a key that unlocks the beginning or initiation of a particular biological or chemical event.
mTORC1 is the central component of the insulin - signaling cascade [insulin / insulin - like growth factor (IGF)-- phosphatidylinositol 3 - kinase (PI3K) pathway)(Fig. 1) that regulates protein synthesis and mRNA translation through 2 primary mechanisms: 1) inactivation of the repressor of mRNA translation, eukaryotic translation initiation factor 4E - binding protein 1 (eIF4E - BP1), and 2) the activation of 70 - kDa ribosomal protein S6 kinase. (academic.oup.com)
They showed genetically that there was an additional response coming from the transcription factor — Forkhead box O (Foxo)-- which in turn enhances the transcription of one of the translational regulators: eukaryotic initiation factor 4E binding protein (4E - BP). (buckinstitute.org)
The structure defines the interactions that RNA polymerase and the transcription initiation factor sigma make with DNA upstream of a gene. (sciencedaily.com)