IndraLab

"We previously showed that eIF3f is phosphorylated by cyclin dependent kinase 11 (CDK11 (p46)) which is an important effector in apoptosis."

"To examine whether phosphorylation of eIF3f by CDK11 p46 regulates its function, we mutated the Ser46 and Thr119 to alanine (A)."

"We demonstrated that eIF3f is directly phosphorylated by CDK11(p46) in vivo."

"These results further indicated that the phosphorylation of eIF3f by CDK11 p46 contributes to its increased association with eIF3 core complex and apoptosis."

"Results from the present study suggest that phosphorylation of eIF3f by CDK11 may contribute to the regulation of protein synthesis and apoptosis."

"To investigate whether the specific eIF3f phosphorylation by CDK11 p46 alters the association between eIF3f and eIF3 core complex, we performed co-immunoprecipitation with specific antibodies against the eIF3b and eIF3f in eIF3f, eIF3f SATA or eIF3f SETE (phosphorylation mimic mutant) transfected cells."

"Our findings are in line with previous observations reporting that endogenous eIF3f can localize at both cytoplasm and nuclear levels. xref During apoptosis, endogenous eIF3f is phosphorylated by CDK11 which is mainly a nuclear protein xref , xref and can assembly with other eIF3 subunits to form nuclear complexes which are involved in functions other than translation initiation, such as ribosome biogenesis that takes place into nucleus. xref The observation of nuclear localization together with the apoptotic effect observed by Annexin V assay strongly suggests that the exogenous and endogenous eIF3f are subjected to similar intracellular processing."

"Based on our observations, the model that we propose depicts that the phosphorylation of eIF3f by CDK11 p46 enhances its binding to different sub-fractions of the eIF3 complex during apoptosis."

"Phosphorylation of eIF3f by CDK11 p46 regulates its function in translation and apoptosis."