Cap-binding complex-dependent translation initiation factor (CTIF)

**Cap-binding complex-dependent translation initiation factor (CTIF)** is a translation initiation factor that acts as a scaffold/adaptor for the pioneer round of translation, during which newly exported messenger RNAs, still bound by the nuclear cap-binding complex (CBC), are translated to facilitate mRNA surveillance and quality control (such as nonsense-mediated mRNA decay)[1][2]. CTIF interacts with CBC-bound mRNAs and recruits eIF3 (through its eIF3g subunit), enabling ribosome small subunit recruitment for translation initiation independent of the canonical eIF4E pathway. This mechanism is distinct from steady-state cap-dependent translation, which is driven by eIF4E and the eIF4F complex. CTIF-mediated translation is proposed to be limited to the perinuclear region and is closely tied to nuclear export and RNA processing steps[1][2]. While often studied in the context of mRNA quality control, its dysregulation may have indirect links to diseases involving aberrant gene expression control, such as cancer[1].

Other names

CTIF

Facilitates translation initiation of newly exported mRNAs by bridging CBC-bound mRNAs with the ribosome, distinct from the classical eIF4E pathway[1][2]