Studies On Focal Adhesion Kinase-like Proteins In Pollen Tube Of Lilium Davidii Duch

Our previous data suggested that the αvβ3 integrin-like proteins should be present in lily pollen ,and probably regulate pollen tube growth through mediating the interation between the tube and extracellular matrix of style.In animal ,integrin is a transmembrane receptor which is clustered and activated when it is linking with ECM protein ,such as Fn,Vn,and then, the activated integrin cause cellular biology response through interaction with intracellular kinase proteins,one of which is the Focal Adhesion Kinase(FAK) .In this study, we tried to investgate the existence of FAK-like protein and its functions in Lily pollen tube.Western blotting analysis showed that a 220KD protein band from germinated pollen cytoplasmic could be recognized by anti-FAK antibody. Preimmune IgG could not cross-react with any protein from lily pollen cytoplasmic matrix .At the same time, Immunoprecipitation experiment by using anti-FAK antibody showed that 220KD FAK-like protein was existent in cytoplasmic matrix of Lily pollen, and it was not probably the protein of tyrosine phosphorylation kinase.Microinjection experiment showed that Lily pollen tube elongation was inhibited by microinjecting human anti-human FAK antibody .Our results indicated that FAK-like protein might be present in cytoplasmic matrix of Lily pollen tube and might be involved in the regulation of pollen tube elongation.