Dissecting the functions of class XI myosins inmoss and Arabidopsis

Abstract

Myosin XI strides along actin tracks at rates of up to 7 μm/s, making it the fastest known processive molecular motor (Tominaga et al., 2003). Class XI myosins are unique to plants and have been implicated in plant growth, intracellular transport, and root hair elongation (Prokhnevsky et al., 2008). Arabidopsis thaliana contains 13 class XImyosins, 6 of which are expressed predominantly in male reproductive tissue and the remainder of which occur in vegetative tissue. The moss Physcomitrella patens harbors only two myosin XI genes, myoXIa and myoXIb, and therefore is an ideal simplified system in which to study myosin XI function. © 2010 American Society of Plant Biologists.