Dear Editor,End-binding protein 1 (EB1),a member of microtubule plusend tracking proteins (+TlPs),plays an important role in the regulation of microtubule dynamics and has been implicated in cancer development (Dong et al.,2010;Gouveia and Akhmanova,2010;Wang et al.,2005).However,it remains poorly understood how EB1 functions are regulated by phosphorylation in mammalian ceils.To map the phosphorylation patte of EB1,we overexpressed GST-EB1 in HeLa cells and enriched GST-EB1 from cell lysates by GST pulldown.The pulldown preparations showed strong serine,threonine,and tyrosine phosphorylation signals in the immunoblots (Fig.S1A).GST-EB1 purified from cells was clearly visualized on the gel prior to in-gel digestion (Fig.S1B).