CKIα or CKIδ is essential in modulating the nuclear export of eukaryotic translation initiation factor 6 (eIF6), a protein with essential nuclear and cytoplasmic roles in biogenesis of the 60S subunit of the eukaryotic ribosome. Phosphorylation of Ser-174 and Ser-175 by CKI promotes nuclear export of eIF6 while dephosphorylation by calcineurin promotes nuclear accumulation of eIF6. It is unclear whether the same mechanism is responsible for eIF6 cycling in yeast and if other kinases also play roles in these processes.
CKI homologs are also implicated in cytoplasmic shuttling of nuclear factor of activated T-cells (NFAT) through observation that the transcription factor Crz1p is phosphorylated by a CKI homolog in yeast.