Overview of the mechanism of cytoskeletal motors based on structure

Abstract

In the last two decades, a wealth of structural and functional knowledge has been obtained for the three major cytoskeletal motor proteins, myosin, kinesin and dynein, which we review here. The cytoskeletal motor proteins myosin and kinesin are structurally similar in the core architecture of their motor domains and have similar force-producing mechanisms that are coupled with the chemical cycles of ATP binding, hydrolysis, Pi release and subsequent ADP release. The force is generated through conformational changes in the motor domain during Pi release and ATP binding in myosin and kinesin, respectively, and then converted into the rotation of the lever arm or neck linker (referred to as a power stroke) through the common structural pathways. On the other hand, the dynein cytoskeletal motor is an AAA+ protein and has a different structure and power stroke mechanism from those of myosins and kinesins. The linker protruding from the AAA+ ring of dynein swings according to the ATPase states, which, presumably, generates force to carry cargos within a cell. The communication mechanism between the track-binding and ATPase domains of dynein is unique because the two helices that presumably slide with respect to each other work as coordinators for these domains. Details of the mechanism underlying the power stroke and interdomain communication were revealed through recent progress in the structural studies of myosin, kinesin and dynein.

Towards a Unified Model of SMC Complex Function

“…To gain insights into the mechanistic basis for the DNA translocation mechanism of condensin, and possibly other SMC protein complexes, we start by considering the working principles of other well-characterized motor proteins, for example the cytoskeletal motor proteins myosin, kinesin or dynein [69]. On a superficial level, these cytoskeletal motors and SMC proteins share the architectural principle of a dimer of ATPase-containing domains that are linked via elongated coiled-coil stalks.…”

High-resolution structures of malaria parasite actomyosin and actin filaments

“…Myosins are a large and diverse family of motor proteins, with >30 classes, found across all eukaryotic organisms (4). Although the myosin classes are functionally and structurally distinct, they share several conserved domains (5,6) and produce force and movement via the same basic mechanism, making cyclical interactions with actin, coupled to the break-down of ATP to ADP and inorganic phosphate (P i ). Most myosins characterized to date move towards the plus-end of actin filaments, with the exception of the reverse-directed, class VI myosins.…”

Metabolic Basis of Creatine in Health and Disease: A Bioinformatics-Assisted Review

“…Cellular processes involving contractile machinery for cell division and fusion (e.g., satellite cell proliferation and myoblast fusion, respectively), cell motility (e.g., sperm motility), organelle and cytoskeletal rearrangement (e.g., morphology remodeling after virus infection), membrane transport and clathrin-mediated vesicular trafficking (e.g., GLUT4 endo-and exocytosis), and signaling transduction (e.g., the MAPK pathway c-Jun NH 2 -terminal kinase [JNK]) rely vastly on motor proteins. These large mechanochemical ATPases traverse the cytoskeleton by producing a force that propels them and their cargo forward by transforming chemical energy into mechanical movement via ATP hydrolysis [194]. There are three classes of motor proteins: (i) myosin isoforms, dyneins, and kinesins.…”