Analysis of the Interaction between hPFTAIRE1 and PLZF in a Yeast Two-hybrid System

<正> hPFTAIRE1 is a Cdc2-related kinase family member.To search its substrates and regulatoryproteins,hPFTAIRE1 was fused to LexA and used as a bait to screen a human brain LexA two-hybrid library.In this screening,seven hPFTAIRE1 interacting proteins,including promyelocytic leukemia zinc finger (PLZF),were obtained.The interaction between PLZF and hPFTAIRE1 was confirmed by β-galactosidase assay andLeu growth activity.PLZF encodes a transcription factor belonging to the POZ/BTB domain and Krüppelzinc finger (POK) family.The highly conserved POZ/BTB domain plays a critical role in protein-proteininteraction.We deleted the POZ/BTB and Krüppel zinc finger domains,respectively,and observed the inter-action between hPFTAIRE1 and truncated PLZFs by liquid β-galactosidase activity assay.A weak interactionwas detected between hPFTAIRE1 and PLZF.We also observed the interaction between PLZF and anotherCdc2-related kinase,PCTAIRE1.A similar result was observed.The interaction between PLZF and hPFTAIRE1or PCTAIRE1 was confirmed by co-immunoprecipitation assay in a yeast system.PLZF is a phosphoproteinand plays multiple roles during cell growth.Our results suggest that hPFTAIRE1 and PCTAIRE1 may playimportant roles in the functional regulation of PLZF.