Molecular Interaction Between 14-3-3? And KIC? Protein

The proteins of 14-3-3 family are highly conserved acidic polypeptides of 28-33 kD that expressed in all eukaryotic species.It is reported that there are more than 150 proteins interacting with 14-3-3 proteins dependent on or independent of Serine/Threonine phosphorylation,which play a important role in cell progress,including cell signaling transduction,cell cycle regulation,cell apoptosis.The 14-3-3 protein family contain seven isoforms ?,?,?,?a,?,? and ?.We performed yeast two-hybrid to screen the human fetal brain cDNA library with 14-3-3? as bait to find the proteins interacting with 14-3-3?.The analysis of nucleotide sequence of insert of one clone indicates that the amino acid sequence encoded by this nucleotide sequence is part of the amino acid sequence of human KIC? protein,which is a novel partner of 14-3-3?.The mammalian kinesin motor protein KIC is a member of the kinesin-3 subfamily.KIC?associates with synaptic transport vesicles in neuronal cells and induces apoptotic cell death.We constructed the truncated mutation of KIC? binding to 14-3-3? by yeast two-hybrid to find out which region involved in this interaction.As a result,14-3-3?bound the 847-1226 amino acids of KICp.Sub-cellular localization analysis showed that both 14-3-3? and KIC? mainly localized in cytoplasm,which indicated that the two proteins may interact each other.GST Pull-down assay confirmed that 14-3-3? could interact with KIC? in vitro,and the interaction is specific.