Binding of Fyn to MAP-2c through an SH3 binding domain. Regulation of the interaction by ERK2.

摘要: Abstract Microtubule-associated protein 2 (MAP-2) isoforms are developmentally expressed in the nervous system and contain a number of functional domains. Adjacent to first repeat microtubule-binding domain is an RTPPKSP motif for binding SH3 To identify SH3-containing proteins that interact with MAP-2, transfections, filter overlay assays, glutathioneS-transferase (GST)-mediated co-immunoprecipitations enzyme-linked immunosorbent assays were performed. Transfections MAP-2a, MAP-2b, MAP-2c constructs into COS7 cells, followed by incubation cell lysates SH3-GST fusion proteins, determined strongest interaction was between non-receptor tyrosine kinase Fyn; however, MAP-2b also bound Grb2. Co-immunoprecipitation Fyn from human fetal homogenates confirmed vivo. MAP-2 synthetic peptides spanning Fyn, regulated phosphorylation. Co-transfections extracellular signal-regulated (ERK2) demonstrated threonine/serine-phosphorylated on its threonine phosphorylation abolished MAP-2c/Fyn binding. Kinase co-transfection phosphorylates MAP-2c. Thus, activation signaling pathways may regulate cytoskeletal dynamics altering state both ERK2 kinase.