Myosin 1E interacts with synaptojanin‐1 and dynamin and is involved in endocytosis

Abstract

Myosin 1E is one of two “long‐tailed” human Class I myosins that contain an SH3 domain within the tail region. SH3 domains of yeast and amoeboid myosins I interact with activators of the Arp2/3 complex, an important regulator of actin polymerization. No binding partners for the SH3 domains of myosins I have been identified in higher eukaryotes. In the current study, we show that two proteins with prominent functions in endocytosis, synaptojanin‐1 and dynamin, bind to the SH3 domain of human Myo1E. Myosin 1E co‐localizes with clathrin‐ and dynamin‐containing puncta at the plasma membrane and this co‐localization requires an intact SH3 domain. Expression of Myo1E tail, which acts in a dominant‐negative manner, inhibits endocytosis of transferrin. Our findings suggest that myosin 1E may contribute to receptor‐mediated endocytosis.